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  • 1.
    Xiong, Sixing
    et al.
    Huazhong Univ Sci and Technol, Peoples R China.
    Hu, Lin
    Huazhong Univ Sci and Technol, Peoples R China.
    Hu, Lu
    Huazhong Univ Sci and Technol, Peoples R China.
    Sun, Lulu
    Huazhong Univ Sci and Technol, Peoples R China.
    Qin, Fei
    Huazhong Univ Sci and Technol, Peoples R China.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhou, Yinhua
    Huazhong Univ Sci and Technol, Peoples R China.
    12.5% Flexible Nonfullerene Solar Cells by Passivating the Chemical Interaction Between the Active Layer and Polymer Interfacial Layer2019In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 31, no 22, article id 1806616Article in journal (Refereed)
    Abstract [en]

    Nonfullerene (NF) organic solar cells (OSCs) have been attracting significant attention in the past several years. It is still challenging to achieve high-performance flexible NF OSCs. NF acceptors are chemically reactive and tend to react with the low-temperature-processed low-work-function (low-WF) interfacial layers, such as polyethylenimine ethoxylated (PEIE), which leads to the S shape in the current-density characteristics of the cells. In this work, the chemical interaction between the NF active layer and the polymer interfacial layer of PEIE is deactivated by increasing its protonation. The PEIE processed from aqueous solution shows more protonated N+ than that processed from isopropyl alcohol solution, observed from X-ray photoelectron spectroscopy. NF solar cells (active layer: PCE-10:IEICO-4F) with the protonated PEIE interfacial layer show an efficiency of 13.2%, which is higher than the reference cells with a ZnO interlayer (12.6%). More importantly, the protonated PEIE interfacial layer processed from aqueous solution does not require a further thermal annealing treatment (only processing at room temperature). The room-temperature processing and effective WF reduction enable the demonstration of high-performance (12.5%) flexible NF OSCs.

  • 2.
    Han, Shaobo
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Alvi, Naveed
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Granlof, Lars
    RISE Bioecon, Sweden.
    Granberg, Hjalmar
    RISE Bioecon, Sweden.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    A Multiparameter Pressure-Temperature-Humidity Sensor Based on Mixed Ionic-Electronic Cellulose Aerogels2019In: ADVANCED SCIENCE, ISSN 2198-3844, Vol. 6, no 8, article id 1802128Article in journal (Refereed)
    Abstract [en]

    Pressure (P), temperature (T), and humidity (H) are physical key parameters of great relevance for various applications such as in distributed diagnostics, robotics, electronic skins, functional clothing, and many other Internet-of-Things (IoT) solutions. Previous studies on monitoring and recording these three parameters have focused on the integration of three individual single-parameter sensors into an electronic circuit, also comprising dedicated sense amplifiers, signal processing, and communication interfaces. To limit complexity in, e.g., multifunctional IoT systems, and thus reducing the manufacturing costs of such sensing/communication outposts, it is desirable to achieve one single-sensor device that simultaneously or consecutively measures P-T-H without cross-talks in the sensing functionality. Herein, a novel organic mixed ion-electron conducting aerogel is reported, which can sense P-T-H with minimal cross-talk between the measured parameters. The exclusive read-out of the three individual parameters is performed electronically in one single device configuration and is enabled by the use of a novel strategy that combines electronic and ionic Seebeck effect along with mixed ion-electron conduction in an elastic aerogel. The findings promise for multipurpose IoT technology with reduced complexity and production costs, features that are highly anticipated in distributed diagnostics, monitoring, safety, and security applications.

  • 3.
    Amin, Sidra
    et al.
    Lulea Univ Technol, Sweden; Shaheed Benazir Bhutto Univ, Pakistan.
    Tahira, Aneela
    Lulea Univ Technol, Sweden.
    Solangi, Amber
    Univ Sindh, Pakistan.
    Beni, Valerio
    Res Inst Sweden, Sweden.
    Morante, J. R.
    Catalonia Inst Energy Res IREC, Spain.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Mazzaro, Raffaello
    Lulea Univ Technol, Sweden.
    Ibupoto, Zafar Hussain
    Lulea Univ Technol, Sweden; Univ Sindh, Pakistan.
    Vomiero, Alberto
    Lulea Univ Technol, Sweden.
    A practical non-enzymatic urea sensor based on NiCo2O4 nanoneedles2019In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, no 25, p. 14443-14451Article in journal (Refereed)
    Abstract [en]

    We propose a new facile electrochemical sensing platform for determination of urea, based on a glassy carbon electrode (GCE) modified with nickel cobalt oxide (NiCo2O4) nanoneedles. These nanoneedles are used for the first time for highly sensitive determination of urea with the lowest detection limit (1 mu M) ever reported for the non-enzymatic approach. The nanoneedles were grown through a simple and low-temperature aqueous chemical method. We characterized the structural and morphological properties of the NiCo2O4 nanoneedles by TEM, SEM, XPS and XRD. The bimetallic nickel cobalt oxide exhibits nanoneedle morphology, which results from the self-assembly of nanoparticles. The NiCo2O4 nanoneedles are exclusively composed of Ni, Co, and O and exhibit a cubic crystalline phase. Cyclic voltammetry was used to study the enhanced electrochemical properties of a NiCo2O4 nanoneedle-modified GCE by overcoming the typical poor conductivity of bare NiO and Co3O4. The GCE-modified electrode is highly sensitive towards urea, with a linear response (R-2 = 0.99) over the concentration range 0.01-5 mM and with a detection limit of 1.0 mu M. The proposed non-enzymatic urea sensor is highly selective even in the presence of common interferents such as glucose, uric acid, and ascorbic acid. This new urea sensor has good viability for urea analysis in urine samples and can represent a significant advancement in the field, owing to the simple and cost-effective fabrication of electrodes, which can be used as a promising analytical tool for urea estimation.

  • 4.
    Xiong, Kunli
    et al.
    Chalmers Univ Technol, Sweden.
    Tordera, Daniel
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering. TNO, Netherlands.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Dahlin, Andreas B.
    Chalmers Univ Technol, Sweden.
    Active control of plasmonic colors: emerging display technologies2019In: Reports on progress in physics (Print), ISSN 0034-4885, E-ISSN 1361-6633, Vol. 82, no 2, article id 024501Article, review/survey (Refereed)
    Abstract [en]

    In recent years there has been a growing interest in the use of plasmonic nanostructures for color generation, a technology that dates back to ancient times. Plasmonic structural colors have several attractive features but once the structures arc prepared the colors arc normally fixed. Lately, several concepts have emerged for actively tuning the colors, which opens up for many new potential applications, the most obvious being novel color displays. In this review we summarize recent progress in active control of plasmonic colors and evaluate them with respect to performance criteria for color displays. It is suggested that actively controlled plasmonic colors are generally less interesting for emissive displays but could be useful for new types of electrochromic devices relying on ambient light (electronic paper). Furthermore, there are several other potential applications such as images to be revealed on demand and colorimetric sensors.

  • 5.
    Gerasimov, Jennifer
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Karlsson, Roger H
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Forchheimer, Robert
    Linköping University, Department of Electrical Engineering, Information Coding. Linköping University, Faculty of Science & Engineering.
    Stavrinidou, Eleni
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel T
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    An Evolvable Organic Electrochemical Transistor for Neuromorphic Applications2019In: ADVANCED SCIENCE, ISSN 2198-3844, Vol. 6, no 7, article id 1801339Article in journal (Refereed)
    Abstract [en]

    An evolvable organic electrochemical transistor (OECT), operating in the hybrid accumulation-depletion mode is reported, which exhibits short-term and long-term memory functionalities. The transistor channel, formed by an electropolymerized conducting polymer, can be formed, modulated, and obliterated in situ and under operation. Enduring changes in channel conductance, analogous to long-term potentiation and depression, are attained by electropolymerization and electrochemical overoxidation of the channel material, respectively. Transient changes in channel conductance, analogous to short-term potentiation and depression, are accomplished by inducing nonequilibrium doping states within the transistor channel. By manipulating the input signal, the strength of the transistor response to a given stimulus can be modulated within a range that spans several orders of magnitude, producing behavior that is directly comparable to short- and long-term neuroplasticity. The evolvable transistor is further incorporated into a simple circuit that mimics classical conditioning. It is forecasted that OECTs that can be physically and electronically modulated under operation will bring about a new paradigm of machine learning based on evolvable organic electronics.

  • 6.
    Janson, Per
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gabrielsson, Erik
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Lee, Keon Jae
    Korea Adv Inst Sci and Technol, South Korea.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    An Ionic Capacitor for Integrated Iontronic Circuits2019In: ADVANCED MATERIALS TECHNOLOGIES, ISSN 2365-709X, Vol. 4, no 4, article id 1800494Article in journal (Refereed)
    Abstract [en]

    Organic electronics, in combination with custom polyelectrolytes, enables solid- and hydrogel-state circuit components using ionic charges in place of the electrons of traditional electronics. This growing field of iontronics leverages anion- and cation-exchange membranes as analogs to n-type and p-type semiconductors, and conjugated polymer electrodes as ion-to-electron converters. To date, the iontronics toolbox includes ionic resistors, ionic diodes, ionic transistors, and analog and digital circuits comprised thereof. Here, an ionic capacitor based on mixed electron-ion conductors is demonstrated. The ionic capacitor resembles the structure of a conventional electrochemical capacitor that is inverted, with an electronically conducting core and two electrolyte ionic conductors. The device is first verified as a capacitor, and then demonstrated as a smoothing element in an iontronic diode bridge circuit driving an organic electronic ion pump (ionic resistor). The ionic capacitor complements the existing iontronics toolbox, enabling more complex and functional ionic circuits, and will thus have implications in a variety of mixed electron-ion conduction technologies.

  • 7.
    Wang, Xin
    et al.
    Department of Printed Electronics, RISE Acreo, Norrköping, Sweden.
    Grimoldi, Andrea
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Hakansson, Karl
    RISE Bioeconomy, Stockholm, Sweden.
    Fall, Andreas
    RISE Bioeconomy, Stockholm, Sweden.
    Granberg, Hjalmar
    RISE Bioeconomy, Stockholm, Sweden.
    Mengistie, Desalegn
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Edberg, Jesper
    Department of Printed Electronics, RISE Acreo, Norrköping, Sweden.
    Engquist, Isak
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Nilsson, David
    Department of Printed Electronics, RISE Acreo, Norrköping, Sweden.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Goran
    Department of Printed Electronics, RISE Acreo, Norrköping, Sweden.
    Anisotropic conductivity of Cellulose-PEDOT:PSS composite materials studied with a generic 3D four-point probe tool2019In: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 66, p. 258-264Article in journal (Refereed)
    Abstract [en]

    The conducive polymer poly(3,4-ethylenedioxythiphene):poly(styrenesulfonate) (PEDOT:PSS) is widely used in organic electronics and printed electronics due to its excellent electronic and ionic conductivity. PEDOT:PSS films exhibit anisotropic conductivities originating from the interplay of film deposition processes and chemical structure. The previous studies found that high boiling point solvent treated PEDOT:PSS exhibits an anisotropy of 3-4 orders magnitude. Even though both the in-plane and out-of-plane conductivities are important for the device performance, the out-of-plane conductivity is rarely studied due to the complexity with the experiment procedure. Cellulose-based paper or films can also exhibit anisotropic behavior due to the combination of their intrinsic fibric structure and film formation process. We have previously developed a conducive paper based on PEDOT:PSS and cellulose which could be used as the electrodes in energy storage devices. In this work we developed a novel measurement set-up for studying the anisotropy of the charge transport in such composite materials. A tool with two parallel plates mounted with spring loaded probes was constructed enabling probing both lateral and vertical directions and resistances from in-plane and out-of-plane directions to be obtained. The measurement results were then input and analyzed with a model based on a transformation method developed by Montgomery, and thus the in-plane and out-of-plane conductivities could be detangled and derived. We also investigated how the conductivity anisotropy depends on the microstructure of the cellulose template onto which the conducive polymer self-organizes. We show that there is a relatively small difference between the in-plane and out-of-plane conductivities which is attributed to the unique 3D-structure of the composites. This new knowledge gives a better understanding of the possibilities and limitations for using the material in electronic and electrochemical devices.

    The full text will be freely available from 2021-12-17 00:01
  • 8.
    Poxson, David
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gabrielsson, Erik
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Bonisoli, Alberto
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Ist Italiano Tecnol, Italy; St Anna Sch Adv Studies, Italy.
    Linderhed, Ulrika
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Res Inst Sweden, Sweden.
    Abrahamsson, Tobias
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Matthiesen, Isabelle
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. KTH Royal Inst Technol, Sweden.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Capillary-Fiber Based Electrophoretic Delivery Device2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 15, p. 14200-14207Article in journal (Refereed)
    Abstract [en]

    Organic electronic ion pumps (OEIPs) are versatile tools for electrophoretic delivery of substances with high spatiotemporal resolution. To date, OEIPs and similar iontronic components have been fabricated using thin-film techniques and often rely on laborious, multistep photolithographic processes. OEIPs have been demonstrated in a variety of in vitro and in vivo settings for controlling biological systems, but the thin-film form factor and limited repertoire of polyelectrolyte materials and device fabrication techniques unnecessarily constrain the possibilities for miniaturization and extremely localized substance delivery, e.g., the greater range of pharmaceutical compounds, on the scale of a single cell. Here, we demonstrate an entirely new OEIP form factor based on capillary fibers that include hyperbranched polyglycerols (dPGs) as the selective electrophoretic membrane. The dPGs enable electrophoretic channels with a high concentration of fixed charges and well-controlled cross-linking and can be realized using a simple one-pot fluidic manufacturing protocol. Selective electrophoretic transport of cations and anions of various sizes is demonstrated, including large substances that are difficult to transport with other OEIP technologies. We present a method for tailoring and characterizing the electrophoretic channels fixed charge concentration in the operational state. Subsequently, we compare the experimental performance of these capillary OEIPs to a computational model and explain unexpected features in the ionic current for the transport and delivery of larger, lower-mobility ionic compounds. From this model, we are able to elucidate several operational and design principles relevant to miniaturized electrophoretic drug delivery technologies in general. Overall, the compactness of the capillary OEIP enables electrophoretic delivery devices with probelike geometries, suitable for a variety of ionic compounds, paving the way for less-invasive implantation into biological systems and for healthcare applications.

  • 9.
    Battocchio, Chiara
    et al.
    Roma Tre Univ, Italy.
    Concolato, Sofia
    Roma Tre Univ, Italy.
    De Santis, Serena
    Roma Tre Univ, Italy.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Iucci, Giovanna
    Roma Tre Univ, Italy.
    Santi, Marta
    Roma Tre Univ, Italy.
    Sotgiu, Giovanni
    Roma Tre Univ, Italy.
    Orsini, Monica
    Roma Tre Univ, Italy.
    Chitosan functionalization of titanium and Ti6Al4V alloy with chloroacetic acid as linker agent2019In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 99, p. 1133-1140Article in journal (Refereed)
    Abstract [en]

    In this work, a new covalent grafting of chitosan on titanium and Ti6Al4V alloy surfaces is reported using chloroacetic acid as linker agent. Good results were obtained both on titanium and on Ti6Al4V alloy. The effect of the surface acid pretreatments on the subsequent functionalization with chitosan is evaluated. The morphological aspect of acid etched metal surfaces before chitosan grafting has been characterized by scanning electron microscopy (SEM). The presence of carboxylic groups on metal surfaces and then the efficiency of chitosan covalent immobilization were detected by Fourier transformed infrared-Attenuated Total Reflectance (FTIR-ATR) and X-Ray photoelectron spectroscopy (XPS). Cyclic voltammetry tests, using the functionalized titanium and Ti6Al4V samples as electrodes, were conducted in different aqueous solutions, to detect the presence of the homogeneous overlayer of chitosan on the surface, and to evaluate the importance of the carboxyl groups as linker agent.

  • 10.
    Modarresi, Mohsen
    et al.
    Ferdawsi Univ Mashhad, Iran.
    Franco Gonzalez, Felipe
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Autonomous Univ Madrid, Spain.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Computational microscopy study of the granular structure and pH dependence of PEDOT:PSS2019In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 12, p. 6699-6711Article in journal (Refereed)
    Abstract [en]

    Computational microscopy based on Martini coarse grained molecular dynamics (MD) simulations of a doped conducting polymer poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (best known as PEDOT:PSS) was performed focussing on the formation of the granular structure and PEDOT crystallites, and the effect of pH on the material morphology. The PEDOT:PSS morphology is shown to be sensitive to the initial distribution of PEDOT and PSS in the solution, and the results of the modelling suggest that the experimentally observed granular structure of PEDOT:PSS can be only obtained if the PEDOT/PSS solution is in the dispersive state in the initial crystallization stages. Variation of the pH is demonstrated to strongly affect the morphology of PEDOT:PSS films, altering their structure between granular-type and homogeneous. It also affects the size of crystallites and the relative arrangement of PEDOT and PSS chains. It is shown that the crystallites in PEDOT:PSS are smaller than those in PEDOT with molecular counterions such as PEDOT:tosylate, which is consistent with the available experimental data. The predicted changes of the PEDOT:PSS morphology with variation of the pH can be tested experimentally, and the calculated atomistic picture of PEDOT:PSS films (not accessible by conventional experimental techniques) is instrumental for understanding the material structure and building realistic models of PEDOT:PSS morphology.

  • 11.
    Håkansson, Anna
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Shahi, Maryam
    Univ Kentucky, KY 40506 USA.
    Brill, Joseph W.
    Univ Kentucky, KY 40506 USA.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Conducting-Polymer Bolometers for Low-Cost IR-Detection Systems2019In: ADVANCED ELECTRONIC MATERIALS, ISSN 2199-160X, Vol. 5, no 6, article id 1800975Article in journal (Refereed)
    Abstract [en]

    Semiconducting polymers are promising materials for manufacturing optoelectronic devices, such as large-area solar cells or small light-emitting diodes, through the use of printing technologies. In their oxidized form, pi-conjugated polymers become good electrical conductors and their optical absorption shifts to the infrared region. It is demonstrated that conducting polymers can be integrated in bolometers for IR detection. A bolometer is a thermally isolated thin device that absorbs IR radiation and translates a temperature change into a change in electrical resistance. While commercial bolometers are usually made of complex architectures comprising several materials (that is, an IR absorbing layer, a conducting layer, and a thermally insulating layer), the first polymer bolometer is demonstrated with a freestanding layer of poly(3,4-ethylene-dioxythiophene) having high IR absorption, low thermal conductivity, and good thermistor action in one single layer. The solution processability of conducting polymers, their compatibility with high-resolution printing technologies, and their unique combination of optoelectronic properties can lead to a breakthrough for low-cost uncooled IR cameras, which are in high demand for security and safety applications.

  • 12.
    Kiefer, David
    et al.
    Chalmers Univ Technol, Sweden.
    Kroon, Renee
    Chalmers Univ Technol, Sweden.
    Hofmann, Anna I.
    Chalmers Univ Technol, Sweden.
    Sun, Hengda
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Giovannitti, Alexander
    Imperial Coll London, England; Imperial Coll London, England.
    Stegerer, Dominik
    Chalmers Univ Technol, Sweden; Tech Univ Chemnitz, Germany.
    Cano, Alexander
    Chalmers Univ Technol, Sweden.
    Hynynen, Jonna
    Chalmers Univ Technol, Sweden.
    Yu, Liyang
    Chalmers Univ Technol, Sweden.
    Zhang, Yadong
    Georgia Inst Technol, GA 30332 USA; Georgia Inst Technol, GA 30332 USA.
    Nai, Dingqi
    Univ Calif Davis, CA 95616 USA.
    Harrelson, Thomas F.
    Univ Calif Davis, CA 95616 USA.
    Sommer, Michael
    Tech Univ Chemnitz, Germany.
    Moule, Adam J.
    Univ Calif Davis, CA 95616 USA.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Marder, Seth R.
    Georgia Inst Technol, GA 30332 USA; Georgia Inst Technol, GA 30332 USA.
    McCulloch, Iain
    Imperial Coll London, England; Imperial Coll London, England; King Abdullah Univ Sci and Technol, Saudi Arabia.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Mueller, Christian
    Chalmers Univ Technol, Sweden.
    Double doping of conjugated polymers with monomer molecular dopants2019In: Nature Materials, ISSN 1476-1122, E-ISSN 1476-4660, Vol. 18, no 2, p. 149-+Article in journal (Refereed)
    Abstract [en]

    Molecular doping is a crucial tool for controlling the charge-carrier concentration in organic semiconductors. Each dopant molecule is commonly thought to give rise to only one polaron, leading to a maximum of one donor: acceptor charge-transfer complex and hence an ionization efficiency of 100%. However, this theoretical limit is rarely achieved because of incomplete charge transfer and the presence of unreacted dopant. Here, we establish that common p-dopants can in fact accept two electrons per molecule from conjugated polymers with a low ionization energy. Each dopant molecule participates in two charge-transfer events, leading to the formation of dopant dianions and an ionization efficiency of up to 200%. Furthermore, we show that the resulting integer charge-transfer complex can dissociate with an efficiency of up to 170%. The concept of double doping introduced here may allow the dopant fraction required to optimize charge conduction to be halved.

  • 13.
    Wang, Suhao
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fazzi, Daniele
    Univ Cologne, Germany.
    Puttisong, Yuttapoom
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jafari, Mohammad Javad
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Chen, Zhihua
    Flexterra Corp, IL 60077 USA.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Andreasen, Jens W.
    Tech Univ Denmark, Denmark.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Facchetti, Antonio
    Flexterra Corp, IL 60077 USA; Northwestern Univ, IL 60208 USA; Northwestern Univ, IL 60208 USA.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Effect of Backbone Regiochemistry on Conductivity, Charge Density, and Polaron Structure of n-Doped Donor-Acceptor Polymers2019In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 31, no 9, p. 3395-3406Article in journal (Refereed)
    Abstract [en]

    We investigated the influence of backbone regiochemistry on the conductivity, charge density, and polaron structure in the widely studied n-doped donor-acceptor polymer poly[N,N-bis(2-octyldodecyl)-1,4,5,8-naphthalenediimide-2,6-diyl]-alt-5,5-(2,2-bithiophene) [P-(NDI2OD-T2)]. In contrast to classic semicrystalline polymers such as poly(3-hexylthiophene) (P3HT), the regioirregular (RI) structure of the naphthalenediimide (NDI)-bithiophene (T2) backbone does not alter the intramolecular steric demand of the chain versus the regioregular (RR) polymer, yielding RI-P(NDI2OD-T2) with similar energetics and optical features as its RR counterpart. By combining the electrical, UV-vis/infrared, X-ray diffraction, and electron paramagnetic resonance data and density functional theory calculations, we quantitatively characterized the conductivity, aggregation, crystallinity, and charge density, and simulated the polaron structures, molecular vibrations, and spin density distribution of RR-/RI-P(NDI2OD-T2). Importantly, we observed that RI-P(NDI2OD-T2) can be doped to a greater extent compared to its RR counterpart. This finding is remarkable and contrasts benchmark P3HT, allowing us to uniquely study the role of regiochemistry on the charge-transport properties of n-doped donor-acceptor polymers.

  • 14.
    Wang, Chuanfei
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Ni, Shaofei
    Department of Chemistry, South University of Science and Technology, Shenzhen, China.
    Braun, Slawomir
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Effects of water vapor and oxygen on non-fullerene small molecule acceptors2019In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 7, no 4, p. 879-886Article in journal (Refereed)
    Abstract [en]

    Due to the rapid development of non-fullerene acceptors (NFAs), the efficiency of organic solar cells is steadily being improved. The stability of organic solar cells also is expected to be enhanced with the introduction of the NFAs, yet the stability of NFAs themselves have been less investigated to date. In this paper, the stability of a set of typical NFAs was studied in situ employing photoelectron spectroscopy. The studied molecules show higher resistance to water vapor and thermal stress compared to fullerenes. For water vapor exposure, the highest occupied molecular orbital (HOMO) of NFAs undergoes only minor and reversible changes and the NFAs/substrate work function stays constant. Exposure to oxygen gas significantly modified the electronic structure of the NFAs and the effect was only partially reversible by annealing. However, the presence of water vapor was shown to slow down the degradation caused by oxygen. This is in stark contrast to fullerenes that undergo irreversible degradation upon water vapor exposure.

  • 15.
    Lach, Stefan
    et al.
    Univ Kaiserslautern, Germany.
    Altenhof, Anna
    Univ Kaiserslautern, Germany.
    Shi, Shengwei
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering. Wuhan Inst Technol, Peoples R China.
    Fahlman, Mats
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ziegler, Christiane
    Univ Kaiserslautern, Germany.
    Electronic and magnetic properties of a ferromagnetic cobalt surface by adsorbing ultrathin films of tetracyanoethylene2019In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 21, no 28, p. 15833-15844Article in journal (Refereed)
    Abstract [en]

    Ultrathin films of tetracyanoethylene (TCNE) on Co(100) were investigated by means of spin-integrated and spin-resolved photoemission spectroscopy ((sp-)UPS), X-ray photoemission spectroscopy (XPS), near edge X-ray absorption fine-structure spectroscopy (NEXAFS), and X-ray magnetic circular dichroism (XMCD). We found a coverage-dependent modulation of the interface dipole and a switching between a metallic and a resistive spin filtering at the interface triggered by two distinct adsorption geometries of TCNE. The strongest hybridization and spin structure modifications are found at low coverage with a face-on adsorption geometry indicating changes in the distance between the surface Co atoms beneath. TCNE has the potential to manipulate the magnetic moments in the Co surface itself, including the possibility of magnetic hardening effects. In summary, the system TCNE/Co offers an experimentally rather easy and controllable way to build up a stable molecular platform stabilizing the reactive ferromagnetic Co surface and customizing the electronic and magnetic properties of the resulting spinterface simultaneously. This makes this system very attractive for spintronic applications as an alternative, less reactive but highly spin polarized foundation beside graphene-based systems.

  • 16.
    Ghosh, Sarbani
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gueskine, Viktor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Electronic Structures and Optical Absorption of N-Type Conducting Polymers at Different Doping Levels2019In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 25, p. 15467-15476Article in journal (Refereed)
    Abstract [en]

    Theoretical understanding of the electronic structure and optical transitions in n-doped conducting polymers is still controversial for polaronic and bipolaronic states and is completely missing for the case of a high doping level. In the present paper, the electronic structure and optical properties of the archetypical n-doped conducting polymer, double-stranded benzimidazo-benzophenanthroline ladder (BBL), are studied using the density functional theory (DFT) and the time dependent DFT method. We find that a polaronic state in the BBL chain is a spin-resolved doublet where the spin degeneracy is lifted. The ground state of two electrons corresponds to a triplet polaron pair, which is in stark contrast to a commonly accepted picture where two electrons are postulated to form a spinless bipolaron. The total spin gradually increases until the reduction level reaches c(red) = 100% (i.e., one electron per monomer unit). With further increase of the reduction level, the total spin decreases until it becomes 0 for the reduction level c(red) = 200%. The calculated results reproduce the experimentally observed spin signal without any phenomenological parameters. A detailed analysis of the evolution of the electronic structure of BBL and its absorption spectra with increase in reduction level is presented. The calculated UV-vis-NIR spectra are compared with the available experimental results. The electronic structure and optical absorption for different reduction levels presented here are generic to a wide class of conducting polymers, which is illustrated by the corresponding calculations for another archetypical conducting polymer, poly(3,4-ethylenedioxythiophene) (best known as PEDOT).

  • 17.
    Wadnerkar, Nitin Shriram
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Exploring Hydrogen Storage in PEDOT: A Computational Study2019In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 4, p. 2066-2074Article in journal (Refereed)
    Abstract [en]

    A reliable hydrogen-based energy technology requires promising materials for safe storage and transport of hydrogen. Here, the storage of hydrogen in the organic polymer poly(3,4-ethylenedioxythiophene) (PEDOT) is explored using density functional theory calculations. It is demonstrated that hydrogen chemisorption on PEDOT is feasible with the maximum gravimetric uptake of similar to 2.8 wt % in ambient condition, whereas physisorption is possible only at very low temperatures or at high pressure. The Gibbs absorption energies, electronic structure, and absorption spectra are calculated for the cases of chemisorption of a single hydrogen atom, a hydrogen pair, and hydrogen saturated chain for both neutral and oxidized PEDOT. Various experimental routes for PEDOT hydrogenations are discussed.

  • 18.
    Yang, Jianming
    et al.
    East China Normal Univ, Peoples R China.
    Xiong, Shaobing
    East China Normal Univ, Peoples R China.
    Qu, Tianyi
    Soochow Univ, Peoples R China.
    Zhang, Yuexing
    Soochow Univ, Peoples R China.
    He, Xiaoxiao
    East China Normal Univ, Peoples R China.
    Guo, Xuewen
    East China Normal Univ, Peoples R China.
    Zhao, Qiuhua
    East China Normal Univ, Peoples R China.
    Braun, Slawomir
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Chen, Jinquan
    East China Normal Univ, Peoples R China.
    Xu, Jianhua
    East China Normal Univ, Peoples R China.
    L, Yanqing I
    Soochow Univ, Peoples R China.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Duan, Chungang
    East China Normal Univ, Peoples R China; Shanxi Univ, Peoples R China.
    Tang, Jianxin
    Soochow Univ, Peoples R China.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Bao, Qinye
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering. East China Normal Univ, Peoples R China; Shanxi Univ, Peoples R China.
    Extremely Low-Cost and Green Cellulose Passivating Perovskites for Stable and High-Performance Solar Cells2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 14, p. 13491-13498Article in journal (Refereed)
    Abstract [en]

    The fast evolution of metal halide perovskite solar cells has opened a new chapter in the field of renewable energy. High-quality perovskite films as the active layers are essential for both high efficiency and long-term stability. Here, the perovskite films with enlarged crystal grain size and decreased defect density are fabricated by introducing the extremely low-cost and green polymer, ethyl cellulose (EC), into the perovskite layer. The addition of EC triggers hydrogen bonding interactions between EC and the perovskite, passivating the charge defect traps at the grain boundaries. The long chain of EC further acts as a scaffold for the perovskite structure, eliminating the annealing-induced lattice strain during the film fabrication process. The resulting devices with the EC additive exhibit a remarkably enhanced average power conversion efficiency from 17.11 to 19.27% and an improvement of all device parameters. The hysteresis index is found to decrease by three times from 0.081 to 0.027, which is attributed to suppressed ion migration and surface charge trapping. In addition, the defect passivation by EC significantly improves the environmental stability of the perovskite films, yielding devices that retain 80% of their initial efficiency after 30 days in ambient air at 45% relative humidity, whereas the pristine devices without EC fully degrade. This work provides a low-cost and green avenue for passivating defects that improves both the efficiency and operational stability of perovskite solar cells.

  • 19.
    Abrahamsson, Tobias
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Poxson, David
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gabrielsson, Erik
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Sandberg, Mats
    RISE Acreo AB, Sweden.
    Simon, Daniel T
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Formation of Monolithic Ion-Selective Transport Media Based on "Click" Cross-Linked Hyperbranched Polyglycerol2019In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 7, article id 484Article in journal (Refereed)
    Abstract [en]

    In the emerging field of organic bioelectronics, conducting polymers and ion-selective membranes are combined to form resistors, diodes, transistors, and circuits that transport and process both electronic and ionic signals. Such bioelectronics concepts have been explored in delivery devices that translate electronic addressing signals into the transport and dispensing of small charged biomolecules at high specificity and spatiotemporal resolution. Manufacturing such "iontronic" devices generally involves classical thin film processing of polyelectrolyte layers and insulators followed by application of electrolytes. This approach makes miniaturization and integration difficult, simply because the ion selective polyelectrolytes swell after completing the manufacturing. To advance such bioelectronics/iontronics and to enable applications where relatively larger molecules can be delivered, it is important to develop a versatile material system in which the charge/size selectivity can be easily tailormade at the same time enabling easy manufacturing of complex and miniaturized structures. Here, we report a one-pot synthesis approach with minimal amount of organic solvent to achieve cationic hyperbranched polyglycerol films for iontronics applications. The hyperbranched structure allows for tunable pre multi-functionalization, which combines available unsaturated groups used in crosslinking along with ionic groups for electrolytic properties, to achieve a one-step process when applied in devices for monolithic membrane gel formation with selective electrophoretic transport of molecules.

  • 20.
    Brooke, Robert
    et al.
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering. Acreo, Sweden.
    Edberg, Jesper
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Acreo, Sweden.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Engquist, Isak
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Greyscale and Paper Electrochromic Polymer Displays by UV Patterning2019In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, no 2, article id 267Article in journal (Refereed)
    Abstract [en]

    Electrochromic devices have important implications as smart windows for energy efficient buildings, internet of things devices, and in low-cost advertising applications. While inorganics have so far dominated the market, organic conductive polymers possess certain advantages such as high throughput and low temperature processing, faster switching, and superior optical memory. Here, we present organic electrochromic devices that can switch between two high-resolution images, based on UV-patterning and vapor phase polymerization of poly(3,4-ethylenedioxythiophene) films. We demonstrate that this technique can provide switchable greyscale images through the spatial control of a UV-light dose. The color space was able to be further altered via optimization of the oxidant concentration. Finally, we utilized a UV-patterning technique to produce functional paper with electrochromic patterns deposited on porous paper, allowing for environmentally friendly electrochromic displays.

  • 21.
    Berggren, Magnus
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Malliaras, George G.
    Univ Cambridge, England.
    How conducting polymer electrodes operate2019In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 364, no 6437, p. 233-234Article in journal (Other academic)
    Abstract [en]

    n/a

  • 22.
    Fahlman, Mats
    et al.
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Laboratory of Organic Electronics.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gueskine, Viktor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel T
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Laboratory of Organic Electronics.
    Interfaces in organic electronics2019In: Nature Reviews Materials, E-ISSN 2058-8437Article in journal (Refereed)
    Abstract [en]

    Undoped, conjugated, organic molecules and polymers possess properties of semiconductors, including the electronic structure and charge transport, which can be readily tuned by chemical design. Moreover, organic semiconductors (OSs) can be n-doped or p-doped to become organic conductors and can exhibit mixed electronic and ionic conductivity. Compared with inorganic semiconductors and metals, organic (semi)conductors possess a unique feature: no insulating oxide forms on their surface when exposed to air. Thus, OSs form clean interfaces with many materials, including metals and other OSs. OS–metal and OS–OS interfaces have been intensely investigated over the past 30 years, from which a consistent theoretical description has emerged. Since the 2000s, increased attention has been paid to interfaces in organic electronics that involve dielectrics, electrolytes, ferroelectrics and even biological organisms. In this Review, we consider the central role of these interfaces in the function of organic electronic devices and discuss how the physico-chemical properties of the interfaces govern the interfacial transport of light, excitons, electrons and ions, as well as the transduction of electrons into the molecular language of cells.

  • 23.
    Bao, Qinye
    et al.
    East China Normal Univ, Peoples R China.
    Braun, Slawomir
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Wang, Chuan Fei
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Interfaces of (Ultra)thin Polymer Films in Organic Electronics2019In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 6, no 1, article id 1800897Article, review/survey (Refereed)
    Abstract [en]

    In this short review the energy level alignment of interfaces involving solution-processed conjugated polymer (and soluble small molecules) films is described. Some general material properties of conjugated polymers and their solution-processed films are introduced, and the basic physics involved in energy level alignment at their interfaces is then discussed. An overview of energy level bending in (ultra)thin conjugated polymer films (often referred to as "band bending") is given and the effects of ion-containing interlayers typically used in organic electronic devices such as polymer light emitting diodes and organic bulk heterojunction solar cells are explored. The review finishes by describing a few of the available computational models useful for predicting and/or modeling energy level alignment at interfaces of solution-processed polymer films and discusses their respective strengths and weaknesses.

    The full text will be freely available from 2019-09-30 13:12
  • 24.
    Berggren, Magnus
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Stavrinidou, Eleni
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ion Electron-Coupled Functionality in Materials and Devices Based on Conjugated Polymers2019In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 31, no 22, article id 1805813Article, review/survey (Refereed)
    Abstract [en]

    The coupling between charge accumulation in a conjugated polymer and the ionic charge compensation, provided from an electrolyte, defines the mode of operation in a vast array of different organic electrochemical devices. The most explored mixed organic ion-electron conductor, serving as the active electrode in these devices, is poly(3,4-ethyelenedioxythiophene) doped with polystyrelensulfonate (PEDOT:PSS). In this progress report, scientists of the Laboratory of Organic Electronics at Linkoping University review some of the achievements derived over the last two decades in the field of organic electrochemical devices, in particular including PEDOT:PSS as the active material. The recently established understanding of the volumetric capacitance and the mixed ion-electron charge transport properties of PEDOT are described along with examples of various devices and phenomena utilizing this ion-electron coupling, such as the organic electrochemical transistor, ionic-electronic thermodiffusion, electrochromic devices, surface switches, and more. One of the pioneers in this exciting research field is Prof. Olle Inganas and the authors of this progress report wish to celebrate and acknowledge all the fantastic achievements and inspiration accomplished by Prof. Inganas all since 1981.

  • 25.
    Cherian, Dennis
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Armgarth, Astrid
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Beni, Valerio
    Res Inst Sweden, Sweden.
    Linderhed, Ulrika
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Res Inst Sweden, Sweden.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Nilsson, David
    Res Inst Sweden, Sweden.
    Simon, Daniel
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Large-area printed organic electronic ion pumps2019In: FLEXIBLE AND PRINTED ELECTRONICS, ISSN 2058-8585, Vol. 4, no 2, article id 022001Article in journal (Refereed)
    Abstract [en]

    Biological systems use a large variety of ions and molecules of different sizes for signaling. Precise electronic regulation of biological systems therefore requires an interface which translates the electronic signals into chemically specific biological signals. One technology for this purpose that has been developed during the last decade is the organic electronic ion pump (OEIP). To date, OEIPs have been fabricated by micropatterning and labor-intensive manual techniques, hindering the potential application areas of this promising technology. Here we show, for the first time, fully screen-printed OEIPs. We demonstrate a large-area printed design with manufacturing yield amp;gt;90%. Screen-printed cation- and anion-exchange membranes are both demonstrated with promising ion selectivity and performance, with transport verified for both small ions (Na+,K+,Cl-) and biologically-relevant molecules (the cationic neurotransmitter acetylcholine, and the anionic anti-inflammatory salicylic acid). These advances open the iontronics toolbox to the world of printed electronics, paving the way for a broader arena for applications.

  • 26.
    Zhang, Shuai
    et al.
    West Pomeranian Univ Technol, Poland.
    Shi, Xiaoze
    West Pomeranian Univ Technol, Poland.
    Chen, Xuecheng
    West Pomeranian Univ Technol, Poland; Chinese Acad Sci, Peoples R China.
    Zhang, Dengsong
    Shanghai Univ, Peoples R China.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Zhang, Zhibin
    Uppsala Univ, Sweden.
    Chu, Paul K.
    City Univ Hong Kong, Peoples R China; City Univ Hong Kong, Peoples R China.
    Tang, Tao
    Chinese Acad Sci, Peoples R China.
    Mijowska, Ewa
    West Pomeranian Univ Technol, Poland.
    Large-Scale and Low-Cost Motivation of Nitrogen-Doped Commercial Activated Carbon for High-Energy-Density Supercapacitor2019In: ACS APPLIED ENERGY MATERIALS, ISSN 2574-0962, Vol. 2, no 6, p. 4234-4243Article in journal (Refereed)
    Abstract [en]

    The growing requirement for high-performance energy-storage devices has spurred the development of supercapacitors, but the low energy density remains a technical hurdle. In this work, porous nitrogen-doped activated carbon (NAC) is prepared on a large scale from commercial activated carbon (AC) and inexpensive chemicals by a one-step method. The NAC material with 3.1 wt % nitrogen has a high specific surface area of 1186 m(2) g(-1) and shows a specific capacitance of 427 F g(-1) in a symmetric cell with an aqueous electrolyte. 98.2% of the capacity is reserved after 20 000 cycles at 20 A g(-1). The energy densities of the NAC are 17.2 and 87.8 Wh kg(-1) in acidic and organic electrolytes, respectively. Moreover, this simple process is readily scalable to address commercial demand and can be extended to the motivation of a variety of carbon based materials with poor capacitances.

  • 27.
    Wang, Zhen
    et al.
    KTH Royal Inst Technol, Sweden.
    Ouyang, Liangqi
    KTH Royal Inst Technol, Sweden.
    Tian, Weiqian
    KTH Royal Inst Technol, Sweden.
    Erlandsson, Johan
    KTH Royal Inst Technol, Sweden.
    Marais, Andrew
    KTH Royal Inst Technol, Sweden.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wagberg, Lars
    KTH Royal Inst Technol, Sweden.
    Hamedi, Mahiar Max
    KTH Royal Inst Technol, Sweden.
    Layer-by-Layer Assembly of High-Performance Electroactive Composites Using a Multiple Charged Small Molecule2019In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, no 32, p. 10367-10373Article in journal (Refereed)
    Abstract [en]

    Layer-by-layer (LbL) assembly is a versatile tool for fabricating multilayers with tailorable nanostructures. LbL, however, generally relies on polyelectrolytes, which are mostly insulating and induce large interlayer distances. We demonstrate a method in which we replace polyelectrolytes with the smallest unit capable of LbL self-assembly: a molecule with multiple positive charges, tris(3-aminopropyl)amine (TAPA), to fabricate LbL films with negatively charged single-walled carbon nanotubes (CNTs). TAPA introduces less defects during the LbL build-up and results in more efficient assembly of films with denser micromorphology. Twenty bilayers of TAPA/CNT showed a low sheet resistance of 11 k Omega, a high transparency of 91% at 500 nm, and a high electronic conductivity of 1100 S/m on planar substrates. We also fabricated LbL films on porous foams with a conductivity of 69 mS/m and used them as electrodes for supercapacitors with a high specific capacitance of 43 F/g at a discharging current density of 1 A/g.

  • 28.
    Ibupoto, Zafar Hussain
    et al.
    Division of Material Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden; Dr. M.A Kazi Institute of Chemistry University of Sindh Jamshoro, Sindh, Pakistan.
    Tahira, Aneela
    Division of Material Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    Tang, PengYi
    Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, Catalonia, Spain; Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, Sant Adrià del Besòs, Barcelona, Catalonia, Spain.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Morante, Joan Ramon
    Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, Sant Adrià del Besòs, Barcelona, Catalonia, Spain.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Arbiol, Jordi
    Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, Catalonia, Spain; ICREA, Pg. Lluís Companys 23, Barcelona, Catalonia, Spain.
    Vagin, Mikhail
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Vomiero, Alberto
    Division of Material Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden.
    MoSx@NiO Composite Nanostructures: An Advanced Nonprecious Catalyst for Hydrogen Evolution Reaction in Alkaline Media2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 7, article id 1807562Article in journal (Refereed)
    Abstract [en]

    The design of the earth-abundant, nonprecious, efficient, and stable electrocatalysts for efficient hydrogen evolution reaction (HER) in alkaline media is a hot research topic in the field of renewable energies. A heterostructured system composed of MoSx deposited on NiO nanostructures (MoSx@NiO) as a robust catalyst for water splitting is proposed here. NiO nanosponges are applied as cocatalyst for MoS2 in alkaline media. Both NiO and MoS2@NiO composites are prepared by a hydrothermal method. The NiO nanostructures exhibit sponge-like morphology and are completely covered by the sheet-like MoS2. The NiO and MoS2 exhibit cubic and hexagonal phases, respectively. In the MoSx@NiO composite, the HER experiment in 1 m KOH electrolyte results in a low overpotential (406 mV) to produce 10 mA cm(-2) current density. The Tafel slope for that case is 43 mV per decade, which is the lowest ever achieved for MoS2-based electrocatalyst in alkaline media. The catalyst is highly stable for at least 13 h, with no decrease in the current density. This simple, cost-effective, and environmentally friendly methodology can pave the way for exploitation of MoSx@NiO composite catalysts not only for water splitting, but also for other applications such as lithium ion batteries, and fuel cells.

    The full text will be freely available from 2020-01-02 12:00
  • 29.
    Pirhashemi, Mahsa
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. University of Mohaghegh Ardabili, Iran.
    Elhag, Sami
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Elhadi Adam, Rania
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Habibi-Yangjeh, Aziz
    University of Mohaghegh Ardabili, Iran.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Nur, Omer
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    n–n ZnO–Ag2CrO4 heterojunction photoelectrodes with enhanced visible-light photoelectrochemical properties2019In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, no 14, p. 7992-8001Article in journal (Refereed)
    Abstract [en]

    In this study, ZnO nanorods (NRs) were hydrothermally grown on an Au-coated glass substrate at a relatively low temperature (90 °C), followed by the deposition of Ag2CrO4 particles via a successive ionic layer adsorption and reaction (SILAR) route. The content of the Ag2CrO4 particles on ZnO NRs was controlled by changing the number of SILAR cycles. The fabricated ZnO–Ag2CrO4 heterojunction photoelectrodes were subjected to morphological, structural, compositional, and optical property analyses; their photoelectrochemical (PEC) properties were investigated under simulated solar light illumination. The photocurrent responses confirmed that the ability of the ZnO–Ag2CrO4 heterojunction photoelectrodes to separate the photo-generated electron–hole pairs is stronger than that of bare ZnO NRs. Impressively, the maximum photocurrent density of about 2.51 mA cm−2 at 1.23 V (vs. Ag/AgCl) was measured for the prepared ZnO–Ag2CrO4 photoelectrode with 8 SILAR cycles (denoted as ZnO–Ag2CrO4-8), which exhibited about 3-fold photo-enhancement in the current density as compared to bare ZnO NRs (0.87 mA cm−2) under similar conditions. The improvement in photoactivity was attributed to the ideal band gap and high absorption coefficient of the Ag2CrO4 particles, which resulted in improved solar light absorption properties. Furthermore, an appropriate annealing treatment was proven to be an efficient process to increase the crystallinity of Ag2CrO4 particles deposited on ZnO NRs, which improved the charge transport characteristics of the ZnO–Ag2CrO4-8 photoelectrode annealed at 200 °C and increased the performance of the photoelectrode. The results achieved in the present work present new insights for designing n–n heterojunction photoelectrodes for efficient and cost-effective PEC applications and solar-to-fuel energ

  • 30.
    Chen, Shangzhi
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Kuhne, Philipp
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Stanishev, Vallery
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Knight, Sean
    Univ Nebraska, NE 68588 USA.
    Brooke, Robert
    RISE Acreo, Sweden.
    Petsagkourakis, Ioannis
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Schubert, Mathias
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Univ Nebraska, NE 68588 USA; Leibniz Inst Polymerforsch Dresden eV, Germany.
    Darakchieva, Vanya
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    On the anomalous optical conductivity dispersion of electrically conducting polymers: ultra-wide spectral range ellipsometry combined with a Drude-Lorentz model2019In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 7, no 15, p. 4350-4362Article in journal (Refereed)
    Abstract [en]

    Electrically conducting polymers (ECPs) are becoming increasingly important in areas such as optoelectronics, biomedical devices, and energy systems. Still, their detailed charge transport properties produce an anomalous optical conductivity dispersion that is not yet fully understood in terms of physical model equations for the broad range optical response. Several modifications to the classical Drude model have been proposed to account for a strong non-Drude behavior from terahertz (THz) to infrared (IR) ranges, typically by implementing negative amplitude oscillator functions to the model dielectric function that effectively reduce the conductivity in those ranges. Here we present an alternative description that modifies the Drude model via addition of positive-amplitude Lorentz oscillator functions. We evaluate this so-called Drude-Lorentz (DL) model based on the first ultra-wide spectral range ellipsometry study of ECPs, spanning over four orders of magnitude: from 0.41 meV in the THz range to 5.90 eV in the ultraviolet range, using thin films of poly(3,4-ethylenedioxythiophene): tosylate (PEDOT: Tos) as a model system. The model could accurately fit the experimental data in the whole ultrawide spectral range and provide the complex anisotropic optical conductivity of the material. Examining the resonance frequencies and widths of the Lorentz oscillators reveals that both spectrally narrow vibrational resonances and broader resonances due to localization processes contribute significantly to the deviation from the Drude optical conductivity dispersion. As verified by independent electrical measurements, the DL model accurately determines the electrical properties of the thin film, including DC conductivity, charge density, and (anisotropic) mobility. The ellipsometric method combined with the DL model may thereby become an effective and reliable tool in determining both optical and electrical properties of ECPs, indicating its future potential as a contact-free alternative to traditional electrical characterization.

  • 31.
    Jakesova, Marie
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Silverå Ejneby, Malin
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Derek, Vedran
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Schmidt, Tony
    Med Univ Graz, Austria.
    Gryszel, Maciej
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Brask, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Schindl, Rainer
    Med Univ Graz, Austria.
    Simon, Daniel
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Elinder, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Glowacki, Eric
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Optoelectronic control of single cells using organic photocapacitors2019In: Science Advances, E-ISSN 2375-2548, Vol. 5, no 4, article id eaav5265Article in journal (Refereed)
    Abstract [en]

    Optical control of the electrophysiology of single cells can be a powerful tool for biomedical research and technology. Here, we report organic electrolytic photocapacitors (OEPCs), devices that function as extracellular capacitive electrodes for stimulating cells. OEPCs consist of transparent conductor layers covered with a donor-acceptor bilayer of organic photoconductors. This device produces an open-circuit voltage in a physiological solution of 330 mV upon illumination using light in a tissue transparency window of 630 to 660 nm. We have performed electrophysiological recordings on Xenopus laevis oocytes, finding rapid (time constants, 50 mu s to 5 ms) photoinduced transient changes in the range of 20 to 110 mV. We measure photoinduced opening of potassium channels, conclusively proving that the OEPC effectively depolarizes the cell membrane. Our results demonstrate that the OEPC can be a versatile nongenetic technique for optical manipulation of electrophysiology and currently represents one of the simplest and most stable and efficient optical stimulation solutions.

  • 32.
    Seitanidou, Maria S
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tybrandt, Klas
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel T
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Overcoming transport limitations in miniaturized electrophoretic delivery devices2019In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 19, no 8, p. 1427-1435Article in journal (Refereed)
    Abstract [en]

    Organic electronic ion pumps (OEIPs) have been used for delivery of biological signaling compounds, at high spatiotemporal resolution, to a variety of biological targets. The miniaturization of this technology provides several advantages, ranging from better spatiotemporal control of delivery to reduced invasiveness for implanted OEIPs. One route to miniaturization is to develop OEIPs based on glass capillary fibers that are filled with a polyelectrolyte (cation exchange membrane, CEM). These devices can be easily inserted and brought into close proximity to targeted cells and tissues and could be considered as a starting point for other fiber-based OEIP and iontronic technologies enabling favorable implantable device geometries. While characterizing capillary OEIPs we observed deviations from the typical linear current-voltage behavior. Here we report a systematic investigation of these irregularities by performing experimental characterizations in combination with computational modelling. The cause of the observed irregularities is due to concentration polarization established at the OEIP inlet, which in turn causes electric field-enhanced water dissociation at the inlet. Water dissociation generates protons and is typically problematic for many applications. By adding an ion-selective cap that separates the inlet from the source reservoir this effect is then, to a large extent, suppressed. By increasing the surface area of the inlet with the addition of the cap, the concentration polarization is reduced which thereby allows for significantly higher delivery rates. These results demonstrate a useful approach to optimize transport and delivery of therapeutic substances at low concentrations via miniaturized electrophoretic delivery devices, thus considerably broadening the opportunities for implantable OEIP applications.

  • 33.
    Bai, Sai
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Univ Oxford, England.
    Da, Peimei
    Univ Oxford, England.
    Li, Cheng
    Univ Bayreuth, Germany; Xiamen Univ, Peoples R China.
    Wang, Zhiping
    Univ Oxford, England.
    Yuan, Zhongcheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fu, Fan
    Empa-Swiss Federal Laboratories for Materials Science and Technology, Duebendorf, Switzerland.
    Kawecki, Maciej
    Empa, Switzerland; Univ Basel, Switzerland.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Sakai, Nobuya
    Univ Oxford, England.
    Wang, Jacob Tse-Wei
    CSIRO Energy, Australia.
    Huettner, Sven
    Univ Bayreuth, Germany.
    Buecheler, Stephan
    Empa Swiss Fed Labs Mat Sci and Technol, Switzerland.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Univ Oxford, England.
    Snaith, Henry J.
    Univ Oxford, England.
    Planar perovskite solar cells with long-term stability using ionic liquid additives2019In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 571, no 7764, p. 245-250Article in journal (Refereed)
    Abstract [en]

    Solar cells based on metal halide perovskites are one of the most promising photovoltaic technologies(1-4). Over the past few years, the long-term operational stability of such devices has been greatly improved by tuning the composition of the perovskites(5-9), optimizing the interfaces within the device structures(10-13), and using new encapsulation techniques(14,15). However, further improvements are required in order to deliver a longer-lasting technology. Ion migration in the perovskite active layer-especially under illumination and heat-is arguably the most difficult aspect to mitigate(16-18). Here we incorporate ionic liquids into the perovskite film and thence into positive-intrinsic-negative photovoltaic devices, increasing the device efficiency and markedly improving the long-term device stability. Specifically, we observe a degradation in performance of only around five per cent for the most stable encapsulated device under continuous simulated full-spectrum sunlight for more than 1,800 hours at 70 to 75 degrees Celsius, and estimate that the time required for the device to drop to eighty per cent of its peak performance is about 5,200 hours. Our demonstration of long-term operational, stable solar cells under intense conditions is a key step towards a reliable perovskite photovoltaic technology.

  • 34.
    Kang, Evan
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Ekinge, Hugo
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Platen High Sch, Sweden.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Plasmonic fanoholes: on the gradual transition from suppressed to enhanced optical transmission through nanohole arrays in metal films of increasing film thickness2019In: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 9, no 3, p. 1404-1415Article in journal (Refereed)
    Abstract [en]

    We study the evolution from suppressed to enhanced optical transmission through metal nanohole arrays with increasing film thickness. Due to Fano interferences, the plasmon resonances gradually shift from transmission dips for ultrathin films to peaks for thick films, accompanied by a Fano asymmetry parameter that increases with film thickness. For intermediate thicknesses, both peaks and dips in transmission are far from the plasmon resonances, and hence, also far from the spectral positions of maximum light absorption and nearfield enhancements. Calculations for various hole diameters and periodicities confirm the universality of our conclusions. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

  • 35.
    Zozoulenko, Igor
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Singh, Amritpal
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Chalmers Univ Technol, Sweden.
    Singh, Sandeep Kumar
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Gueskine, Viktor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Polarons, Bipolarons, And Absorption Spectroscopy of PEDOT2019In: ACS APPLIED POLYMER MATERIALS, ISSN 2637-6105, Vol. 1, no 1, p. 83-94Article in journal (Refereed)
    Abstract [en]

    Electronic structure and optical absorption spectra of poly(3,4-ethyl-enedioxythiophene) (PEDOT) for different oxidation levels were studied using density functional theory (DFT) and time-dependent DFT. It is shown, that the DFT-based predictions for the polaronic and bipolaronic states and the nature of corresponding optical transitions are qualitatively different from the widely used traditional picture based on semi-empirical pre-DFT approaches that still dominate the current literature. On the basis of the results of our calculations, the experimental Vis/NIR absorbance spectroscopy and the electron paramagnetic resonance spectroscopy are re-examined, and a new interpretation of the measured spectra and the spin signal, which is qualitatively different from the traditional interpretation, is provided. The findings and conclusions concerning the nature of polaronic and bipolaronic states, band structure and absorption spectra presented for PEDOT, are generic for a wide class of conducting polymers (such as polythiophenes and their derivatives) that have a similar structure of monomer units.

  • 36.
    Zhao, Dan
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Martinelli, Anna
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg.
    Willfahrt, Andreas
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Fischer, Thomas
    Innovative Applications of The Printing Technologies, Stuttgart Media University.
    Bernin, Diana
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg.
    Ullah Khan, Zia
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Shahi, Maryam
    Department of Physics and Astronomy, University of Kentucky.
    Brill, Joseph
    Department of Physics and Astronomy, University of Kentucky.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Polymer gels with tunable ionic Seebeck coefficient for ultra-sensitive printed thermopiles2019In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, article id 1093Article in journal (Refereed)
    Abstract [en]

    Measuring temperature and heat flux is important for regulating any physical, chemical, and biological processes. Traditional thermopiles can provide accurate and stable temperature reading but they are based on brittle inorganic materials with low Seebeck coefficient, and are difficult to manufacture over large areas. Recently, polymer electrolytes have been proposed for thermoelectric applications because of their giant ionic Seebeck coefficient, high flexibility and ease of manufacturing. However, the materials reported to date have positive Seebeck coefficients, hampering the design of ultra-sensitive ionic thermopiles. Here we report an “ambipolar” ionic polymer gel with giant negative ionic Seebeck coefficient. The latter can be tuned from negative to positive by adjusting the gel composition. We show that the ion-polymer matrix interaction is crucial to control the sign and magnitude of the ionic Seebeck coefficient. The ambipolar gel can be easily screen printed, enabling large-area device manufacturing at low cost.

  • 37.
    Qin, Leiqian
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Tao, Quanzheng
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Halim, Joseph
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Persson, Per O A
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Rosén, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Jinan Univ, Peoples R China.
    Polymer-MXene composite films formed by MXene-facilitated electrochemical polymerization for flexible solid-state microsupercapacitors2019In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 60, p. 734-742Article in journal (Refereed)
    Abstract [en]

    Materials with tailored properties are crucial for high performance electronics applications. Hybrid materials composed of inorganic and organic components can possess unique merits for broad application by synergy between the advantages the respective material type offers. Here we demonstrate a novel electrochemical polymerization (EP) enabled by a 2D transition metal carbide MXene for obtaining conjugated polymer-MXene composite films deposited on conducting substrates without using traditional electrolytes, indispensable compounds for commonly electrochemical polymerization. The universality of the process provides a novel approach for EP allowing fast facile process for obtaining different new polymer/MXene composites with controlled thickness and micro-pattern. Furthermore, high performance microsupercapacitors and asymmetric microsupercapacitors are realized based on the excellent composites benefiting from higher areal capacitance, better rate capabilities and lower contact resistance than conventional electropolymerized polymers. The AMSCs exhibit a maximum areal capacitance of 69.5 mF cm(-2), an ultrahigh volumetric energy density (250.1 mWh cm(-3)) at 1.6 V, and excellent cycling stability up to 10000 cycles. The excellent electrochemical properties of the composite polymerized with MXene suggest a great potential of the method for various energy storage applications.

  • 38.
    Willfahrt, Andreas
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Stuttgart Media Univ, Germany.
    Steiner, Erich
    Stuttgart Media Univ, Germany.
    Hoetzel, Jonas
    Stuttgart Media Univ, Germany.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Printable acid-modified corn starch as non-toxic, disposable hydrogel-polymer electrolyte in supercapacitors2019In: Applied Physics A: Materials Science & Processing, ISSN 0947-8396, E-ISSN 1432-0630, Vol. 125, no 7, article id 474Article in journal (Refereed)
    Abstract [en]

    Corn starch and citric acid, two low-cost and abundant materials, were used for establishing a novel screen printable hydrogel for printed electronics applications. Corn starch was modified with citric acid by melt-blending; the so obtained thermoplastic starch was ground to powder and added to a water-starch suspension. Ultrasonication was used to prepare hydrogels of different citric acid concentrations. The most promising hydrogel contained 10% citric acid by weight, provided an ionic conductivity of (2.30 +/- 0.07)mScm(-1) and appropriate rheological properties for screen and stencil printing. The hydrogel shows superb printability and prolonged stability against degradation. The corn starch hydrogel was used as printable gel polymer electrolyte in fully printed supercapacitors. The specific capacitance of the printed supercapacitor reached 54Fg(-1). The printable hydrogel-polymer electrolyte is easy to produce without in-depth chemical knowledge, is based on widely used and non-toxic materials, and may be used as a functional layer in other printed electronics applications such as printed batteries.

  • 39.
    Xu, Weidong
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Hu, Qi
    Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Bai, Sai
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Bao, Chunxiong
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen, China.
    Miao, Yanfeng
    Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Yuan, Zhongcheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Borzda, Tetiana
    Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia, Milan, Italy.
    Barker, Alex J.
    Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia, Milan, Italy.
    Tyukalova, Elizaveta
    School of Materials Science and Engineering, Nanyang Technological University (NTU), Singapore, Singapore.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Kawecki, Maciej
    Laboratory for Nanoscale Materials Science, Empa, Dubendorf, Switzerland / Department of Physics, University of Basel, Basel, Switzerland.
    Wang, Heyong
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Yan, Zhibo
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, P. R. China.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Shi, Xiaobo
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Zhang, Wenjing
    International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen, China.
    Duchamp, Martial
    School of Materials Science and Engineering, Nanyang Technological University (NTU), Singapore, Singapore.
    Liu, Jun-Ming
    Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, P. R. China.
    Petrozza, Annamaria
    Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia, Milan, Italy.
    Wang, Jianpu
    Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Liu, Li-Min
    Beijing Computational Science Research Center, Beijing, China / chool of Physics, Beihang University, Beijing, China .
    Huang, Wei
    ey Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China / Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), Xi’an, China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Rational molecular passivation for high-performance perovskite light-emitting diodes2019In: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 13, no 6, p. 418-424Article in journal (Refereed)
    Abstract [en]

    A major efficiency limit for solution-processed perovskite optoelectronic devices, for example light-emitting diodes, is trap-mediated non-radiative losses. Defect passivation using organic molecules has been identified as an attractive approach to tackle this issue. However, implementation of this approach has been hindered by a lack of deep understanding of how the molecular structures influence the effectiveness of passivation. We show that the so far largely ignored hydrogen bonds play a critical role in affecting the passivation. By weakening the hydrogen bonding between the passivating functional moieties and the organic cation featuring in the perovskite, we significantly enhance the interaction with defect sites and minimize non-radiative recombination losses. Consequently, we achieve exceptionally high-performance near-infrared perovskite light-emitting diodes with a record external quantum efficiency of 21.6%. In addition, our passivated perovskite light-emitting diodes maintain a high external quantum efficiency of 20.1% and a wall-plug efficiency of 11.0% at a high current density of 200 mA cm−2, making them more attractive than the most efficient organic and quantum-dot light-emitting diodes at high excitations.

  • 40.
    Diacci, Chiara
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Lee, Jee Woong
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Janson, Per
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Dufil, Gwennael
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Méhes, Gábor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Simon, Daniel
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Stavrinidou, Eleni
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Real-Time Monitoring of Glucose Export from Isolated Chloroplasts Using an Organic Electrochemical Transistor2019In: Advanced Materials Technologies, ISSN 2365-709X, article id 1900262Article in journal (Refereed)
    Abstract [en]

    Biosensors based on organic electrochemical transistors (OECT) are attractive devices for real-time monitoring of biological processes. The direct coupling between the channel of the OECT and the electrolyte enables intimate interfacing with biological environments at the same time bringing signal amplification and fast sensor response times. So far, these devices are mainly applied to mammalian systems; cells or body fluids for the development of diagnostics and various health status monitoring technology. Yet, no direct detection of biomolecules from cells or organelles is reported. Here, an OECT glucose sensor applied to chloroplasts, which are the plant organelles responsible for the light-to-chemical energy conversion of the photosynthesis, is reported. Real-time monitoring of glucose export from chloroplasts in two distinct metabolic phases is demonstrated and the transfer dynamics with a time resolution of 1 min is quantified, thus reaching monitoring dynamics being an order of magnitude better than conventional methods.

  • 41.
    Sardar, Samim
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wojcik, Pawel
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Kang, Evan
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Shanker, Ravi
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Structural coloration by inkjet-printing of optical microcavities and metasurfaces2019In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 7, no 28, p. 8698-8704Article in journal (Refereed)
    Abstract [en]

    Structural color generation by plasmonic and other means has attracted significant interest as a solution to avoid inks based on dyes. Prominent advantages include better robustness compared with organic dyes while also providing high chromaticity and brightness in ultrathin films. However, lack of cheap and scalable fabrication techniques has so far limited structural coloration to only a few applications and functional devices. Here, we demonstrate reflective (plasmonic) structural coloration at high resolution by inkjet printing on non-patterned surfaces. The method is flexible, scalable to large areas, and avoids complicated or costly fabrication steps. Optical microcavities on flexible plastic substrates were made starting with an inkjet-printed silver film as a bottom mirror. Inkjet-printed organic dielectric micropixels then served as the spacer layer, resulting in optical microcavities with reflective structural colors after coating with a thin semi-transparent metallic top layer. Optimization of ink formulation allowed for uniform pixels with minimum coffee stain effects as well as control of spacer thickness (around 50-150 nm) and color by varying the solid content of the ink. We investigate the possibility to obtain red, green and blue (RGB) pixels and demonstrate the improvement of particularly the blue coloration using wavelength-dependent plasmon absorption of gold nanoislands as a top mirror. Inkjet printing of optical microcavities and plasmonic cavities may find use in various applications, such as reflective displays in color.

  • 42.
    Li, Guowei
    et al.
    Max Planck Inst Chem Phys Solids, Germany.
    Fu, Chenguang
    Max Planck Inst Chem Phys Solids, Germany.
    Wu, Jiquan
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Rao, Jiancun
    Univ Maryland, MD 20742 USA.
    Liou, Sz-Chian
    Univ Maryland, MD 20742 USA.
    Xu, Xijin
    Univ Jinan, Peoples R China.
    Shao, Baiqi
    Chinese Acad Sci, Peoples R China.
    Liu, Kai
    Chinese Acad Sci, Peoples R China.
    Liu, Enke
    Chinese Acad Sci, Peoples R China.
    Kumar, Nitesh
    Max Planck Inst Chem Phys Solids, Germany.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Gooth, Johannes
    Max Planck Inst Chem Phys Solids, Germany.
    Auffermann, Gudrun
    Max Planck Inst Chem Phys Solids, Germany.
    Sun, Yan
    Max Planck Inst Chem Phys Solids, Germany.
    Felser, Claudia
    Max Planck Inst Chem Phys Solids, Germany.
    Zhang, Baomin
    Univ Jinan, Peoples R China.
    Synergistically creating sulfur vacancies in semimetal-supported amorphous MoS2 for efficient hydrogen evolution2019In: Applied Catalysis B: Environmental, ISSN 0926-3373, E-ISSN 1873-3883, Vol. 254Article in journal (Refereed)
    Abstract [en]

    The presence of elemental vacancies in materials are inevitable according to statistical thermodynamics, which will decide the chemical and physical properties of the investigated system. However, the controlled manipulation of vacancies for specific applications is a challenge. Here we report a facile method for creating large concentrations of S vacancies in the inert basal plane of MoS2 supported on semimetal CoMoP2. With a small applied potential, S atoms can be removed in the form of H2S due to the optimized free energy of formation. The existence of vacancies favors electron injection from the electrode to the active site by decreasing the contact resistance. As a consequence, the catalytic current is increased by 221% with the vacancy-rich MoS2 as electrocatalyst for hydrogen evolution reaction (HER). A small overpotential of 75 mV is needed to deliver a current density of 10 mA cm(-2), which is considered among the best values achieved for MoS2. It is envisaged that this work may provide a new strategy for utilizing the semimetal phase for structuring MoS2 into a multi-functional material.

  • 43.
    Shiran Chaharsoughi, Mina
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhao, Dan
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jonsson, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Thermodiffusion-Assisted Pyroelectrics-Enabling Rapid and Stable Heat and Radiation Sensing2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 28, article id 1900572Article in journal (Refereed)
    Abstract [en]

    Sensors for monitoring temperature, heat flux, and thermal radiation are essential for applications such as electronic skin. While pyroelectric and thermoelectric effects are suitable candidates as functional elements in such devices, both concepts show individual drawbacks in terms of zero equilibrium signals for pyroelectric materials and small or slow response of thermoelectric materials. Here, these drawbacks are overcome by introducing the concept of thermodiffusion-assisted pyroelectrics, which combines and enhances the performance of pyroelectric and ionic thermoelectric materials. The presented integrated concept provides both rapid initial response upon heating and stable synergistically enhanced signals upon prolonged exposure to heat stimuli. Likewise, incorporation of plasmonic metasurfaces enables the concept to provide both rapid and stable signals for radiation-induced heating. The performance of the concept and its working mechanism can be explained by ion-electron interactions at the interface between the pyroelectric and ionic thermoelectric materials.

  • 44.
    Hwang, Sunbin
    et al.
    KIST, South Korea.
    Jang, Sukjae
    KIST, South Korea.
    Kang, Minji
    KIST, South Korea.
    Bae, Sukang
    KIST, South Korea.
    Lee, Seoung-Ki
    KIST, South Korea.
    Hong, Jae-Min
    KIST, South Korea.
    Lee, Sang Hyun
    Chonnam Natl Univ, South Korea.
    Wang, Gunuk
    Korea Univ, South Korea.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Kim, Tae-Wook
    KIST, South Korea.
    Two-in-One Device with Versatile Compatible Electrical Switching or Data Storage Functions Controlled by the Ferroelectricity of P(VDF-TrFE) via Photocrosslinking2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 28, p. 25358-25368Article in journal (Refereed)
    Abstract [en]

    Organic electronics demand new platforms that can make integrated circuits and undergo mass production while maintaining diverse functions with high performance. The field-effect transistor has great potential to be a multifunctional device capable of sensing, data processing, data storage, and display. Currently, transistor-based devices cannot be considered intrinsic multifunctional devices because all installed functions are mutually coupled. Such incompatibilities are a crucial barrier to developing an all-in-one multifunctional device capable of driving each function individually. In this study, we focus on the decoupling of electric switching and data storage functions in an organic ferroelectric memory transistor. To overcome the incompatibility of each function, the high permittivity needed for electrical switching and the ferroelectricity needed for data storage become compatible by restricting the motion of poly(vinylidene fluoride-trifluoroethylene) via photocrosslinking with bis-perfluorobenzoazide. The two-in-one device consisting of a photocrosslinked ferroelectric layer exhibits reversible and individual dual-functional operation as a typical transistor with nonvolatile memory. Moreover, a p-MOS depletion load inverter composed of the two transistors with different threshold voltages is also demonstrated by simply changing only one of the threshold voltages by polarization switching. We believe that the two-in-one device will be considered a potential component of integrated organic logic circuits, including memory, in the future.

  • 45.
    Guo, Xuewen
    et al.
    East China Normal Univ, Peoples R China.
    Li, Danqin
    East China Normal Univ, Peoples R China.
    Zhang, Yuexing
    Soochow Univ, Peoples R China.
    Jan, Ming
    Shanghai Jiao Tong Univ, Peoples R China.
    Xu, Jinqiu
    Shanghai Jiao Tong Univ, Peoples R China.
    Wang, Zhiquan
    East China Normal Univ, Peoples R China.
    Li, Bo
    East China Normal Univ, Peoples R China.
    Xiong, Shaobing
    East China Normal Univ, Peoples R China.
    Li, Yanqing
    Soochow Univ, Peoples R China.
    Liu, Feng
    Shanghai Jiao Tong Univ, Peoples R China.
    Tang, Jianxin
    Soochow Univ, Peoples R China.
    Duan, Chungang
    East China Normal Univ, Peoples R China; Shanxi Univ, Peoples R China.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Bao, Qinye
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering. East China Normal Univ, Peoples R China; Shanxi Univ, Peoples R China; Soochow Univ, Peoples R China.
    Understanding the effect of N2200 on performance of J71: ITIC bulk heterojunction in ternary non-fullerene solar cells2019In: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 71, p. 65-71Article in journal (Refereed)