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  • 1.
    Wang, Xin
    et al.
    Department of Printed Electronics, RISE Acreo, Norrköping, Sweden.
    Grimoldi, Andrea
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Hakansson, Karl
    RISE Bioeconomy, Stockholm, Sweden.
    Fall, Andreas
    RISE Bioeconomy, Stockholm, Sweden.
    Granberg, Hjalmar
    RISE Bioeconomy, Stockholm, Sweden.
    Mengistie, Desalegn
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Edberg, Jesper
    Department of Printed Electronics, RISE Acreo, Norrköping, Sweden.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Nilsson, David
    Department of Printed Electronics, RISE Acreo, Norrköping, Sweden.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    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 tool2019Inngår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 66, s. 258-264Artikkel i tidsskrift (Fagfellevurdert)
    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.

    Fulltekst tilgjengelig fra 2021-12-17 00:01
  • 2.
    Brooke, Robert
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten. Acreo, Sweden.
    Edberg, Jesper
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten. Acreo, Sweden.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Jonsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Greyscale and Paper Electrochromic Polymer Displays by UV Patterning2019Inngår i: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, nr 2, artikkel-id 267Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 3.
    Edberg, Jesper
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten. RISE Acreo, Sweden.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten. Stellenbosch University, South Africa.
    Boosting the capacity of all-organic paper supercapacitors using wood derivatives2018Inngår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, nr 1, s. 145-152Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Printed and flexible organic electronics is a steadily expanding field of research and applications. One of the most attractive features of this technology is the possibility of large area and high throughput production to form low-cost electronics on different flexible substrates. With an increasing demand for sustainable energy production, low-cost and large volume technologies to store high-quality energy become equally important. These devices should be environmentally friendly with respect to their entire life cycle. Supercapacitors and batteries based on paper hold great promise for such applications due to the low cost and abundance of cellulose and other forest-derived components. We report a thick-film paper-supercapacitor system based on cellulose nanofibrils, the mixed ion-electron conducting polymer PEDOT: PSS and sulfonated lignin. We demonstrate that the introduction of sulfonated lignin into the cellulose-conducting polymer system increases the specific capacitance from 110 to 230 F g(-1) and the areal capacitance from 160 mF cm(-2) to 1 F cm(-2). By introducing lignosulfonate also into the electrolyte solution, equilibrium, with respect to the concentration of the redox molecule, was established between the electrode and the electrolyte, thus allowing us to perform beyond 700 charge/discharge cycles with no observed decrease in performance.

  • 4.
    Brooke, Robert
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten.
    Edberg, Jesper
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Iandolo, Donata
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten. Ecole Natl Super Mines, France.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Controlling the electrochromic properties of conductive polymers using UV-light2018Inngår i: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 6, nr 17, s. 4663-4670Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The phenomenon of electrochromism in conductive polymers is well known and has been exploited in many scientific reports. Using a newly developed patterning technique for conductive polymers, we manufactured high-resolution electrochromic devices from the complementary polymers PEDOT and polypyrrole. The technique, which combines UV-light exposure with vapor phase polymerization, has previously only been demonstrated with the conductive polymer PEDOT. We further demonstrated how the same technique can be used to control the optical properties and the electrochromic contrast in these polymers. Oxidant exposure to UV-light prior to vapor phase polymerization showed a reduction in polymer electrochromic contrast allowing high-resolution (100 mu m) patterns to completely disappear while applying a voltage bias due to their optical similarity in one redox state and dissimilarity in the other. This unique electrochromic property enabled us to construct devices displaying images that appear and disappear with the change in applied voltage. Finally, a modification of the electrochromic device architecture permitted a dual image electrochromic device incorporating patterned PEDOT and patterned polypyrrole on the same electrode, allowing the switching between two different images.

  • 5.
    Chaharsoughi, Mina Shiran
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Tordera, Daniel
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Grimoldi, Andrea
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Fabiano, Simone
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Jonsson, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Hybrid Plasmonic and Pyroelectric Harvesting of Light Fluctuations2018Inngår i: Advanced Optical Materials, ISSN 2162-7568, E-ISSN 2195-1071Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    State-of-the-art solar energy harvesting systems based on photovoltaic technology require constant illumination for optimal operation. However, weather conditions and solar illumination tend to fluctuate. Here, a device is presented that extracts electrical energy from such light fluctuations. The concept combines light-induced heating of gold nanodisks (acting as plasmonic optical nanoantennas), and an organic pyroelectric copolymer film (poly(vinylidenefluoride-co-trifluoroethylene)), that converts temperature changes into electrical signals. This hybrid device can repeatedly generate current pulses, not only upon the onset of illumination, but also when illumination is blocked. Detailed characterization highlights the key role of the polarization state of the copolymer, while the copolymer thickness has minor influence on performance. The results are fully consistent with plasmon-assisted pyroelectric effects, as corroborated by combined optical and thermal simulations that match the experimental results. Owing to the tunability of plasmonic resonances, the presented concept is compatible with harvesting near infrared light while concurrently maintaining visible transparency.

  • 6.
    Jiao, Fei
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Edberg, Jesper
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Zhao, Dan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Puzinas, Skomantas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Khan, Zia
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Mäkie, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanostrukturerade material. Linköpings universitet, Tekniska fakulteten.
    Naderi, Ali
    Innventia AB, Sweden.
    Lindstrom, Tom
    Innventia AB, Sweden.
    Odén, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanostrukturerade material. Linköpings universitet, Tekniska fakulteten.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Nanofibrillated Cellulose-Based Electrolyte and Electrode for Paper-Based Supercapacitors2018Inngår i: ADVANCED SUSTAINABLE SYSTEMS, ISSN 2366-7486, Vol. 2, nr 1, artikkel-id UNSP 1700121Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Solar photovoltaic technologies could fully deploy and impact the energy conversion systems in our society if mass-produced energy-storage solutions exist. A supercapacitor can regulate the fluctuations on the electrical grid on short time scales. Their mass-implementation requires the use of abundant materials, biological and organic synthetic materials are attractive because of atomic element abundancy and low-temperature synthetic processes. Nanofibrillated cellulose (NFC) coming from the forest industry is exploited as a three-dimensional template to control the transport of ions in an electrolyte-separator, with nanochannels filled of aqueous electrolyte. The nanochannels are defined by voids in the nanocomposite made of NFC and the proton transporting polymer polystyrene sulfonic acid PSSH. The ionic conductivity of NFC-PSSH composites (0.2 S cm(-1) at 100% relative humidity) exceeds sea water in a material that is solid, feel dry to the finger, but filled of nanodomains of water. A paper-based supercapacitor made of NFC-PSSH electrolyte-separator sandwiched between two paper-based electrodes is demonstrated. Although modest specific capacitance (81.3 F g(-1)), power density (2040 W kg(-1)) and energy density (1016 Wh kg(-1)), this is the first conceptual demonstration of a supercapacitor based on cellulose in each part of the device; which motivates the search for using paper manufacturing as mass-production of energy-storage devices.

  • 7.
    Edberg, Jesper
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Malti, Abdellah
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Granberg, Hjalmar
    RISE Bioeconomy.
    Hamedi, Mahiar M.
    KTH Royal Institute of Technology.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Electrochemical circuits from ‘cut and stick’ PEDOT:PSS-nanocellulose composite2017Inngår i: Flexible and printed electronics, E-ISSN 2058-8585, Vol. 4, nr 2, artikkel-id 045010Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report a flexible self-standing adhesive composite made from PEDOT:PSS and nanofibrillated cellulose. The material exhibits good combined mechanical and electrical characteristics(an elastic modulus of 4.4 MPa, and an electrical conductivity of 30 S cm−1 ). The inherent self-adhesiveness of the material enables it to be laminated and delaminated repeatedly to form and reconfigure devices and circuits. This modular property opens the door for a plethora of applications where reconfigurability and ease-of-manufacturing are of prime importance. We also demonstrate a paper composite with ionic conductivity and combine the two materials to construct electrochemical devices, namely transistors, capacitors and diodes with high values of transconductance, charge storage capacity and current rectification. We have further used these devices to construct digital circuits such as NOT, NAND and NOR logic.

  • 8.
    Fabiano, Simone
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Abdollahi Sani, Negar
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten. RISE Acreo, Sweden.
    Kawahara, Jun
    RISE Acreo, Sweden; LINTEC Corp, Japan.
    Kergoat, Loig
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten. Aix Marseille University, France.
    Nissa, Josefin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Ferroelectric polarization induces electronic nonlinearity in ion-doped conducting polymers2017Inngår i: Science Advances, ISSN 0036-8156, E-ISSN 2375-2548, Vol. 3, nr 6, artikkel-id e1700345Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) is an organic mixed ion-electron conducting polymer. The PEDOT phase transports holes and is redox-active, whereas the PSS phase transports ions. When PEDOT is redox-switched between its semiconducting and conducting state, the electronic and optical properties of its bulk are controlled. Therefore, it is appealing to use this transition in electrochemical devices and to integrate those into large-scale circuits, such as display or memory matrices. Addressability and memory functionality of individual devices, within these matrices, are typically achieved by nonlinear current-voltage characteristics and bistability-functions that can potentially be offered by the semiconductor-conductor transition of redox polymers. However, low conductivity of the semiconducting state and poor bistability, due to self-discharge, make fast operation and memory retention impossible. We report that a ferroelectric polymer layer, coated along the counter electrode, can control the redox state of PEDOT. The polarization switching characteristics of the ferroelectric polymer, which take place as the coercive field is overcome, introduce desired nonlinearity and bistability in devices that maintain PEDOT in its highly conducting and fast-operating regime. Memory functionality and addressability are demonstrated in ferro-electrochromic display pixels and ferro-electrochemical transistors.

  • 9.
    Jafari, Mohammad Javad
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Liu, Jiang
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Ederth, Thomas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Time-Resolved Chemical Mapping in Light-Emitting Electrochemical Cells2017Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, nr 3, s. 2747-2757Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An understanding of the doping and ion distributions in light-emitting electrochemical cells (LECs) is required to approach a realistic conduction model which can precisely explain the electrochemical reactions, p-n junction formation, and ion dynamics in the active layer and to provide relevant information about LECs for systematic improvement of function and manufacture. Here, Fourier-transform infrared (FTIR) microscopy is used to monitor anion density profile and polymer structure in situ and for time-resolved mapping of electrochemical doping in an LEC under bias. The results are in very good agreement with the electrochemical doping model with respect to ion redistribution and formation of a dynamic p-n junction in the active layer. We also physically slow ions by decreasing the working temperature and study frozen-junction formation and immobilization of ions in a fixed-junction LEC device by FTIR imaging. The obtained results show irreversibility of the ion redistribution and polymer doping in a fixed-junction device. In addition, we demonstrate that infrared microscopy is a useful tool for in situ characterization of electroactive organic materials.

  • 10.
    Malti, Abdellah
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Edberg, Jesper
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Granberg, Hjalmar
    Innventia AB, Stockholm.
    Ullah Khan, Zia
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Andreasen, Jens W
    Technical University of Denmark, Roskilde.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Zhao, Dan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Hao
    University of Kentucky, Lexington.
    Yao, Yulong
    University of Kentucky, Lexington.
    Brill, Joseph W
    University of Kentucky, Lexington.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Wågberg, Lars
    KTH Royal Institute of Technology, Stockholm.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    An Organic Mixed Ion–Electron Conductor for Power Electronics2016Inngår i: Advanced Science, ISSN 2198-3844, artikkel-id 1500305Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting nanopaper are exploited in devices which exhibit record values for the charge storage capacitance (1F) in supercapacitors and transconductance (1S) in electrochemical transistors.

  • 11.
    Abdollahi Sani, Negar
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Wang, Xin
    Acreo Swedish ICT AB, Sweden.
    Granberg, Hjalmar
    INNVENTIA AB, Sweden.
    Andersson Ersman, Peter
    Acreo Swedish ICT AB, Sweden.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Dyreklev, Peter
    Acreo Swedish ICT AB, Sweden.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Gustafsson, Göran
    Acreo Swedish ICT AB, Sweden.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Flexible Lamination-Fabricated Ultra-High Frequency Diodes Based on Self-Supporting Semiconducting Composite Film of Silicon Micro-Particles and Nano-Fibrillated Cellulose2016Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, nr 28921Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Low cost and flexible devices such as wearable electronics, e-labels and distributed sensors will make the future "internet of things" viable. To power and communicate with such systems, high frequency rectifiers are crucial components. We present a simple method to manufacture flexible diodes, operating at GHz frequencies, based on self-adhesive composite films of silicon micro-particles (Si-mu Ps) and glycerol dispersed in nanofibrillated cellulose (NFC). NFC, Si-mu Ps and glycerol are mixed in a water suspension, forming a self-supporting nanocellulose-silicon composite film after drying. This film is cut and laminated between a flexible pre-patterned Al bottom electrode and a conductive Ni-coated carbon tape top contact. A Schottky junction is established between the Al electrode and the Si-mu Ps. The resulting flexible diodes show current levels on the order of mA for an area of 2 mm(2), a current rectification ratio up to 4 x 10(3) between 1 and 2 V bias and a cut-off frequency of 1.8 GHz. Energy harvesting experiments have been demonstrated using resistors as the load at 900 MHz and 1.8 GHz. The diode stack can be delaminated away from the Al electrode and then later on be transferred and reconfigured to another substrate. This provides us with reconfigurable GHz-operating diode circuits.

  • 12.
    Edberg, Jesper
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Iandolo, Donata
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Brooke, Robert
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Musumeci, Chiara
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Wenzel Andreasen, Jens
    Technical University of Denmark, Denmark.
    Simon, Daniel
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Evans, Drew
    University of South Australia, Australia.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Patterning and Conductivity Modulation of Conductive Polymers by UV Light Exposure2016Inngår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 26, nr 38, s. 6950-6960Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel patterning technique of conductive polymers produced by vapor phase polymerization is demonstrated. The method involves exposing an oxidant film to UV light which changes the local chemical environment of the oxidant and subsequently the polymerization kinetics. This procedure is used to control the conductivity in the conjugated polymer poly(3,4-ethylenedioxythiophene): tosylate by more than six orders of magnitude in addition to producing high-resolution patterns and optical gradients. The mechanism behind the modulation in the polymerization kinetics by UV light irradiation as well as the properties of the resulting polymer are investigated.

  • 13.
    Ullah Khan, Zia
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Edberg, Jesper
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Max Hamedi, Mahiar
    KTH Royal Institute Technology, Sweden.
    Gabrielsson, Roger
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Granberg, Hjalmar
    Innventia AB, Sweden.
    Wågberg, Lars
    KTH Royal Institute Technology, Sweden.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Thermoelectric Polymers and their Elastic Aerogels2016Inngår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 28, nr 22, s. 4556-4562Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electronically conducting polymers constitute an emerging class of materials for novel electronics, such as printed electronics and flexible electronics. Their properties have been further diversified to introduce elasticity, which has opened new possibility for "stretchable" electronics. Recent discoveries demonstrate that conducting polymers have thermoelectric properties with a low thermal conductivity, as well as tunable Seebeck coefficients - which is achieved by modulating their electrical conductivity via simple redox reactions. Using these thermoelectric properties, all-organic flexible thermoelectric devices, such as temperature sensors, heat flux sensors, and thermoelectric generators, are being developed. In this article we discuss the combination of the two emerging fields: stretchable electronics and polymer thermoelectrics. The combination of elastic and thermoelectric properties seems to be unique for conducting polymers, and difficult to achieve with inorganic thermoelectric materials. We introduce the basic concepts, and state of the art knowledge, about the thermoelectric properties of conducting polymers, and illustrate the use of elastic thermoelectric conducting polymer aerogels that could be employed as temperature and pressure sensors in an electronic-skin.

  • 14.
    Malti, Abdellah
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Edberg, Jesper
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Granberg, Hjalmar
    Innventia AB, Stockholm, Sweden.
    Khan, Zia Ullah
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Andreasen, Jens W.
    Technical University of Denmark, Department of Energy Conversion and Storage, Roskilde, Denmark.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Zhao, Dan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Hao
    Department of Physics and Astronomy, University of Kentucky, Lexington, USA.
    Yao, Ylong
    Department of Physics and Astronomy, University of Kentucky, Lexington, USA.
    Brill, Joseph W.
    Department of Physics and Astronomy, University of Kentucky, Lexington, USA.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Wåberg, Lars
    KTH Royal Institute of Technology, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, and Wallenberg Wood Science Center, Stockholm, Sweden.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Enabling organic power electronics with a cellulose nano-scaffold2015Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Exploiting the nanoscale properties of certain materials enables the creation of new materials with a unique set of properties. Here, we report on an electronic (and ionic) conducting paper based on cellulose nanofibrils (CNF) composited with poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS), which may be facilely processed into large three-dimensional geometries, while keeping unprecedented electronic and ionic conductivities of 140 S/cm and 20 mS/cm, respectively. This is achieved by cladding the CNF with PEDOT:PSS, and trapping an ion-transporting phase in the interstices between these nanofibrils. The unique properties of the resulting nanopaper composite have been used to demonstrate (electrochemical) transistors, supercapacitors and conductors resulting in exceptionally high device parameters, such as an associated transconductance, charge storage capacity and current level beyond 1 S, 1 F and 1 A, respectively.

  • 15.
    Khan, Zia Ullah
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Edberg, Jesper
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Hamedi, Mahiar
    Department of Chemistry and Chemical Biology, Harvard University, Cambridge, USA.
    Gabrielsson, Roger
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Granberg, Hjalmar
    Innventia AB, Stockholm, Sweden.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Nanofibrillated cellulose aerogels functionalized with conducting polymers for thermoelectric and dual-sensing applications2015Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Large amount of heat is wasted in industries, power generation plants and ordinary household appliances. This waste heat, can be a useful input to a thermoelectric generator (TEG) that can convert it to electricity. Conducting polymers (CPs) have been proved as best suited thermoelectric (TE) materials for lower temperatures, being not toxic, abundant in nature and solution processible. So far, CPs have been characterized as thin films, but it needs the third dimension to realize vertical TEGs which is possible by coating it on low thermal conductivity 3D skeletons. In this work, porous bulk cellulose structures have been used as a supporting material and were coated with CPs in various ways. The blend of cellulose and polymer were also freeze-dried, resulting in conducting and soft composites. Those flexible aerogels were utilized as a dual parameter sensor to sense pressure and temperature, based on the concept of thermoelectricity. It opens another application area of sensing, utilizing the thermoelectric phenomenon beyond the prevailing power generation concept. The sensitivity of such materials can be enhanced to make them useful as electronic skin in healthcare and robotics.

  • 16.
    Abdollahi Sani, Negar
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Robertsson, Mats
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Cooper, Philip
    De La Rue Plc, Overton, Hampshire, UK .
    Wang, Xin
    Acreo AB, Norrköping, Sweden.
    Svensson, Magnus
    Acreo AB, Norrköping, Sweden.
    Andersson Ersman, Peter
    Acreo AB, Norrköping, Sweden.
    Norberg, Petronella
    Acreo AB, Norrköping, Sweden.
    Nilsson, Marie
    Acreo AB, Norrköping, Sweden.
    Nilsson, David
    Acreo AB, Norrköping, Sweden.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Hesselbom, Hjalmar
    Hesselbom Innovation and Development HB, Huddinge, Sweden .
    Akesso, Laurent
    De La Rue Plc, Overton, Hampshire, UK .
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan. Acreo AB, Norrköping, Sweden.
    Gustafsson, Goran
    Acreo AB, Norrköping, Sweden.
    All-printed diode operating at 1.6 GHz2014Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 111, nr 33, s. 11943-11948Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Printed electronics are considered for wireless electronic tags and sensors within the future Internet-of-things (IoT) concept. As a consequence of the low charge carrier mobility of present printable organic and inorganic semiconductors, the operational frequency of printed rectifiers is not high enough to enable direct communication and powering between mobile phones and printed e-tags. Here, we report an all-printed diode operating up to 1.6 GHz. The device, based on two stacked layers of Si and NbSi2 particles, is manufactured on a flexible substrate at low temperature and in ambient atmosphere. The high charge carrier mobility of the Si microparticles allows device operation to occur in the charge injection-limited regime. The asymmetry of the oxide layers in the resulting device stack leads to rectification of tunneling current. Printed diodes were combined with antennas and electrochromic displays to form an all-printed e-tag. The harvested signal from a Global System for Mobile Communications mobile phone was used to update the display. Our findings demonstrate a new communication pathway for printed electronics within IoT applications.

  • 17.
    Liu, Jiang
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Half‐Gate Light‐Emitting Electrochemical Transistor to Achieve Centered Emissive Organic p‐n Junction2014Inngår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 18, s. 32-36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Conventional organic light-emitting electrochemical cells show promise for lighting applications but in many cases suffer from unbalanced electrochemical doping. A predominant p-doping over n-doping causes an off-centered emissive p-n junction, which leads to poor power-conversion efficiency. Here, we report a half-gate lightemitting electrochemical transistor (HGLECT), in which a ion-conductive gate made from poly(3,4-ethylenedioxythiophene)-poly-(styrenesulfonate) is employed to combat this problem. The gate material, covering half the channel, is used to enhance the ndoping in this part by employing an appropriate operation protocol. We demonstrate a centered light emission zone, closely following the geometry of the gate material. The HGLECT with centered emission profile is shown to be more efficient than the corresponding LEC without gate electrode, and its n-doping level is measured to be 15%.

  • 18.
    Liu, Jiang
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Organic Reprogrammable Circuits Based on Electrochemically-Formed Diodes2014Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, nr 15, s. 13266-13270Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To simplify the integration of organic electronics, we demonstrate a method for constructing reprogrammable circuits based on organic diodes. The organic p‐n junction diodes consisting of an organic polymers poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene and an electrolyte were formed by electrochemical doping at 70 °C, and stabilized at ‐30 °C. The reversible electrochemical reaction allows for the in‐situ change of the polarity of the organic p‐n junction. By forming diodes with different polarity at different locations, several circuits can be created, such as, logic gates, voltage limiter and AC/DC converter. The as‐made circuitry can be erased and turned into circuitry with other functionality. For example, the diodes of an AND gate can be re‐programmed to form an OR gate. The reprogrammable circuits contain merely two core layers, electrodes and active material, which is promising for large‐area and fully‐printed reconfigurable circuits with facile fabrication.

  • 19.
    Laiho, Ari
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Tran Nguyen, Ha
    University of Mons, Belgium.
    Sinno, Hiam
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Dubois, Philippe
    University of Mons, Belgium.
    Coulembier, Olivier
    University of Mons, Belgium.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Amphiphilic Poly(3-hexylthiophene)-Based Semiconducting Copolymers for Printing of Polyelectrolyte-Gated Organic Field-Effect Transistors2013Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 46, nr 11, s. 4548-4557Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polyelectrolytes are promising electronically insulating layers for low-voltage organic field effect transistors. However, the polyelectrolyte–semiconductor interface is difficult to manufacture due to challenges in wettability. We introduce an amphiphilic semiconducting copolymer which, when spread as a thin film, can change its surface from hydrophobic to hydrophilic upon exposure to water. This peculiar wettability is exploited in the fabrication of polyelectrolyte-gated field-effect transistors operating below 0.5 V. The prepared amphiphilic semiconducting copolymer is based on a hydrophobic regioregular poly(3-hexylthiophene) (P3HT) covalently linked to a hydrophilic poly(sulfonated)-based random block. Such a copolymer is obtained in a three-step strategy combining Grignard metathesis (GRIM), atom transfer radical polymerization (ATRP) processes, and a postmodification method. The structure of the diblock copolymer was characterized using FT-IR, 1H NMR spectroscopy, and gel permeation chromatography (GPC).

  • 20.
    Sinno, Hiam
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Nguyen, Ha Tran
    University of Mons-UMONS, Belgium.
    Hägerström, Anders
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Lindell, Linda
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Coulembier, Olivier
    University of Mons-UMONS, Belgium.
    Dubois, Philippe
    University of Mons-UMONS, Belgium.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Amphiphilic semiconducting copolymer as compatibility layer for printing polyelectrolyte-gated OFETs2013Inngår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 14, nr 3, s. 790-796Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report a method for inkjet-printing an organic semiconductor layer on top of the electrolyte insulator layer in polyelectrolyte-gated OFETs by using a surface modification treatment to overcome the underlying wettability problem at this interface. The method includes depositing an amphiphilic diblock copolymer (P3HT-b-PDMAEMA). This material is designed to have one set of blocks that mimics the hydrophobic properties of the semiconductor (poly(3-hexylthiophene) or P3HT), while the other set of blocks include polar components that improve adhesion to the polyelectrolyte insulator. Contact angle measurements, atomic force microscopy, and X-ray photoelectron spectroscopy confirm formation of the desired surface modification film. Successful inkjet printing of a smooth semiconductor layer allows us to manufacture complete transistor structures that exhibit low-voltage operation in the range of 1 V.

  • 21.
    Sinno, Hiam
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Kergoat, Loig
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Fabiano, Simone
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Bias stress effect in inverters based on polyelectrolyte-gated organic field effect transistors2013Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Prolonged gate bias application causes undesirable operational instabilities in organic transistors involving threshold voltage shift and drain current degradation; an effect known as bias stress. In this paper, we report how this instability is manifested in inverter circuits based on polyelectrolytegated p-type organic field effect transistors (EGOFETs) operating at low voltage. We find that bias stress causes a significant, but recoverable, shift in inverter switching threshold voltage. Measurements with two different polyelectrolytes reveal significant differences in the stressing and recovery behaviour, which is ascribed to the distinct nature of the ion conductive groups in the polyelectrolyte. Moreover, we report a large influence of illumination on the recovery process for one of the polyelectrolytes but not for the other, which demonstrates the need to characterize bias stress behavior for each new materials combination.

  • 22.
    Sinno, Hiam
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Fabiano, Simone
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Bias stress effect in polyelectrolyte-gated organic field-effect transistors2013Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 102, nr 11Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A main factor contributing to bias stress instability in organic transistors is charge trapping of mobile carriers near the gate insulator-semiconductor interface into localized electronic states. In this paper, we study the bias stress behavior in low-voltage (p-type) polyelectrolyte-gated organic field effect transistors (EGOFETs) at various temperatures. Stressing and recovery in these EGOFETs are found to occur six orders of magntiude faster than typical bias stress/recovery reported for dielectric-gated OFETs. The mechanism proposed for EGOFETs involves an electron transfer reaction between water and the charged semiconductor channel that promotes the creation of extra protons diffusing into the polyelectrolyte.

  • 23.
    Liu, Jiang
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan. null.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan. null.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan. null.
    Double-Gate Light-Emitting Electrochemical Transistor: Confining the Organic p-n Junction2013Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 135, nr 33, s. 12224-12227Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In conventional light-emitting electrochemical cells (LECs), an off-centered p-n junction is one of the major drawbacks, as it leads to exciton quenching at one of the charge-injecting electrodes and results in performance instability. To combat this problem, we have developed a new device configuration, the double-gate light-emitting electrochemical transistor (DG-LECT), in which the location of the light-emitting p-n junction can be precisely defined via the position of the two gate terminals. Based on a planar LEC structure, two gate electrodes made from an electrochemically active conducting polymer are employed to predefine the p- and n-doped area of the light-emitting polymer. Thus, a p-n junction is formed in between the p-doped and n-doped regions. We demonstrate a homogeneous and centered p-n junction as well as other predefined junction patterns in these DG-LECT devices. Additionally, we report an electrical model that explains the operation of the DG-LECTs. The DG-LECT device provides a new tool to study the fundamental physics of LECs, as it dissects the key working process of LEC into decoupled p-doping, n-doping, and electroluminescence.

  • 24.
    Wang, Xiaodong
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Larsson, Oscar
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Platt, Duncan
    Acreo AB.
    Nordlinder, Staffan
    WebShape AB.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    An all-printed wireless humidity sensor label2012Inngår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 166-167, s. 556-561Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Printed electronics promise various kinds of sensor circuit labels, for applications in distributed sensing and monitoring, which can be manufactured using traditional printing tools at very low cost. Elevated humidity levels or water leakages cause tremendous costs in our society, such as in construction industries and in transportations. Distributed monitoring and remote sensing of the humidity level inside walls of buildings and packages is therefore desired and urgently needed. Here, we report a wireless humidity sensor label that is manufactured using screen-printing and dry-phase patterning. The sensor label includes a planar antenna, a tuning capacitor and a printed sensor-capacitor head. Through electromagnetic coupling between a reader and the printed sensor label, changes in humidity level were remotely detected and read-out as a shift of the resonant frequency. The manufacturing process of the humidity sensor label is fully compatible with inexpensive, reel-to-reel processing technologies, thus enabling low cost production.

  • 25.
    Kawahara, Jun
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Andersson Ersman, Peter
    Acreo AB.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Improving the color switch contrast in PEDOT:PSS-based electrochromic displays2012Inngår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 13, nr 3, s. 469-474Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Poly(3,4-ethylenedioxythiophene) chemically doped with poly(styrene sulfonic acid) (PEDOT:PSS) is a material system commonly used as a conductive and transparent coating in several important electronic applications. The material is also electrochemically active and exhibits electrochromic (EC) properties making it suitable as the active element in EC display applications. In this work uniformly coated PEDOT:PSS layers were used both as the pixel electrode and as the counter electrode in EC display components. The pixel and counter electrodes were separated by a whitish opaque and water-based polyelectrolyte and the thicknesses of the two EC layers were varied independently in order to optimize the color contrast of the display element. A color contrast (ΔE, CIE Lab color space) exceeding 40 was obtained with maintained relatively short switching time at an operational voltage less than 2 V.

  • 26.
    Blaudeck, Thomas
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Andersson Ersman, Peter
    Acreo AB, Sweden .
    Sandberg, Mats
    Acreo AB, Sweden .
    Heinz, Sebastian
    Technical University of Chemnitz, Germany .
    Laiho, Ari
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Liu, Jiang
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Baumann, Reinhard R.
    Technical University of Chemnitz, Germany Fraunhofer Institute Elect Nanosyst ENAS, Germany .
    Simplified Large-Area Manufacturing of Organic Electrochemical Transistors Combining Printing and a Self-Aligning Laser Ablation Step2012Inngår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 22, nr 14, s. 2939-2948Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A hybrid manufacturing approach for organic electrochemical transistors (OECTs) on flexible substrates is reported. The technology is based on conventional and digital printing (screen and inkjet printing), laser processing, and post-press technologies. A careful selection of the conductive, dielectric, and semiconductor materials with respect to their optical properties enables a self-aligning pattern formation which results in a significant reduction of the usual registration problems during manufacturing. For the prototype OECTs, based on this technology, on/off ratios up to 600 and switching times of 100 milliseconds at gate voltages in the range of 1 V were obtained.

  • 27.
    Liu, Jiang
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Spatial Control of p-n Junction in an Organic Light-Emitting Electrochemical Transistor2012Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 134, nr 2, s. 901-904Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Low-voltage-operating organic electrochemical light-emitting cells (LECs) and transistors (OECTs) can be realized in robust device architectures, thus enabling easy manufacturing of light sources using printing tools. In an LEC, the p-n junction, located within the organic semiconductor channel, constitutes the active light-emitting element. It is established and fixated through electrochemical p- and n-doping, which are governed by charge injection from the anode and cathode, respectively. In an OECT, the electrochemical doping level along the organic semiconducting channel is controlled via the gate electrode. Here we report the merger of these two devices: the light-emitting electrochemical transistor, in which the location of the emitting p-n junction and the current level between the anode and cathode are modulated via a gate electrode. Light emission occurs at 4 V, and the emission zone can be repeatedly moved back and forth within an interelectrode gap of 500 mu m by application of a 4 V gate bias. In transistor operation, the estimated on/off ratio ranges from 10 to 100 with a gate threshold voltage of -2.3 V and transconductance value between 1.4 and 3 mu S. This device structure opens for new experiments tunable light sources and LECs with added electronic functionality.

  • 28.
    Israr, Muhammad Qadir
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    ul Hasan, Kamran
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Sadaf, Jamil Rana
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Nour, Omer
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Danielsson, B.
    Pure and Applied Biochemistry, Lund University, Box 124, SE-221 00 Lund, Sweden.
    Structural characterization and biocompatible applications of graphene nanosheets for miniaturization of potentiometric cholesterol biosensor2011Inngår i: Journal of Biosensors & Bioelectronics, ISSN 2155-6210, Vol. 2, nr 3Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The potentiometric cholesterol biosensor based on graphene nanosheets has been successfully miniaturized. Cholesterol oxidase (ChOx) has been immobilized onto graphene nanosheets exfoliated on copper wire through the process of physical adsorption,. The presented potentiometric biosensor renders effective selectivity and sensitivity (~82 mV/decade) for the detection of cholesterol biomolecules in 1 × 10−6 M to 1 × 10−3 M logarithmic range and quick output response within ~ 4 sec. The stability and reusability of the biosensor has also been investigated for the above mentioned range of cholesterol concentrations. The enzyme activity measurements on graphene nanosheets are studied using UV-Visible and FTIR spectrophotometers. Additionally, the functioning of the presented biosensor is studied for a range of temperatures (15-70 °C) and pH values (4-9).

  • 29.
    Tehrani, Payman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Robinson, Nathaniel D
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Nilsson, David
    Acreo AB.
    Robertsson, Mats
    Acreo AB.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Printable organic electrochemical circuit to record time-temperature history2010Inngår i: ELECTROCHIMICA ACTA, ISSN 0013-4686, Vol. 55, nr 23, s. 7061-7066Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An electrochemical circuit to record time-temperature history has been realized by using the propagation of over-oxidation fronts in stripes of poly(3,4-ethylenedioxythiopehene) blended with poly(styrenesulfonate) (PEDOT:PSS). The over-oxidation front propagation has been characterized and related to the phase change of polyethylene glycol (PEG) electrolytes. The electrolytes were chosen to have a phase transition in the temperature interval to be monitored, resulting in large conductivity variations and thereby an easily interpreted output. A demonstrator has been fabricated and shown to detect a temperature increase and a following temperature decrease. This very simple device is cheap to produce and could be used to monitor the temperature of packages.

  • 30.
    Liu, Jiang
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Herlogsson, Lars
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Sawadtee, A
    Acreo AB.
    Favia, P
    IMEC.
    Sandberg, M
    Acreo AB.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Vertical polyelectrolyte-gated organic field-effect transistors2010Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 97, s. 103303-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Short-channel, vertically structured organic transistors with a polyelectrolyte as gate insulator are demonstrated. The devices are fabricated using low-resolution, self-aligned, and mask-free photolithography. Owing to the use of a polyelectrolyte, our vertical electrolyte-gated organic field-effect transistors (VEGOFETs), with channel lengths of 2.2 and 0.7 μm, operate at voltages below one volt. The VEGOFETs show clear saturation and switch on and off in 200 μs. A vertical geometry to achieve short-transistor channels and the use of an electrolyte makes these transistors promising candidates for printed logics and drivers with low operating voltage.

  • 31.
    Said, Elias
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Andersson, Peter
    ACREO AB, Bredgatan 34, SE-602 21 Norrköping, Sweden.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Electrochromic display cells driven by an electrolyte-gated organic field-effect transistor2009Inngår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 10, nr 6, s. 1195-1199Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Monolithic integration of an electrolyte-gated organic field-effect transistor (OFET) and an organic electrochromic pixel is reported. Thanks to its versatility, the polyanionic proton conductor poly(styrenesulfonic acid) (PSSH) can serve both as the gate “insulator” in OFETs and as the electrolyte in electrochromic display pixels. Employing identical materials in both the display cells and in the driver transistors is a necessary prerequisite to achieve robust displays possible to manufacture on flexible carriers using printing tools. Smart pixels combining depletion mode electrochemical transistors and electrochromic displays have been reported in the past. Here, an enhancement mode OFET as the driver enables relatively shorter updating times and much simpler addressing and updating schemes.

  • 32.
    Persson, Nils-Ola
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Uvdal, Kajsa
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Almquist, Ola
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Kariis, Hans
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Adsorption of potassium O,O -Di(para-fluorophenyl) dithiophosphate on gold, silver, and copper1999Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 15, nr 23, s. 8161-8169Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Gold, silver, and copper substrates were immersed in aqueous solutions of a simulant mineral flotation agent, potassium O,O-di(para-fluorophenyl) dithiophosphate. The adsorbed molecules on gold were studied in detail with infrared reflection-absorption spectroscopy (IRAS), X-ray photoelectron spectroscopy(XPS), and ellipsometry. The most significant peaks in the IRAS spectra were assigned to the appropriate molecular vibrations and their relative intensities were compared with those found in simulated spectra derived from the isotropic optical constants of corresponding metal salts to deduce the binding and orientation. Moreover, intensity ratios of XPS signals were compared at different takeoff angles to reveal the depth distribution of atoms in the dithiophosphate layers. The following modes of adsorption were deduced: The adsorption on gold takes place by the formation of bonds involving the two sulfur atoms of the flotation agent (bridging coordination), regardless of immersion time and solution concentration. A thin and less organized layer is formed at low exposures. Longer adsorption times with more concentrated solutions give a more dense molecular packing and vertical orientation of the molecules on the surface. Adsorption on silver and copper was studied by IRAS. The adsorption proceeded via a dissolution-precipitation mechanism that manifests itself by less pronounced orientation effects. The intensities of the silver and copper IRAS spectra after long immersion times in concentrated solutions also show the formation of multilayers with some persisting long-range molecular ordering.

  • 33.
    Lestelius, Magnus
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Tengvall, Pentti
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Chaudhury, M. K.
    Lehigh university, USA.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Order/disorder gradients of n-alkanethiols on gold1999Inngår i: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 15, nr 1, s. 57-70Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper explores the interfacial properties of one-dimensional molecular gradients of alkanethiols (HS-(CH2)(n)- X) on gold. The kinetics and thermodynamics of monolayer formation are important issues for these types of mixed molecular assemblies. The influence of chain length difference on the contact angles with hexadecane (HD), theta(a) and theta(r), and the hysteresis, has been studied by employing alkanethiols HS-(CH2)(n)-CH3, with n = 9, 11, 13, 15 and 17, in the preparation of the self-assembled monolayers (SAM) gradients. The contact angles with hexadecane, at the very extreme ends of the gradients, show characteristic values of a highly ordered CH3-like assembly: theta(a) = 45-50 degrees. In the middle of the gradients theta(a) drops noticeably and exhibits values representative for CH2-like polymethylenes, theta(a) = 20-30 degrees, indicating a substantial disordering of the protruding chains of the longer component in the gradient assembly. As expected, the exposure of CH2-groups to the probing liquid increases with increasing differential chain length of the two n-alkanethiol used, in this case eight methylene units. However, the contact angles always display a non-zero value which means that even at a chain length difference of eight methylene units there is a substantial exposure of methyl (CH3) groups to the probing liquid. With infrared reflection-absorption spectroscopy (IRAS) we have monitored the structural behavior of the polymethylene chains along the gradient. We find complementary evidence for disordered chains in the gradient region, and the IRAS results correlate well with the contact angle measurements. (C) 1999 Elsevier Science B.V. All rights reserved.

  • 34.
    Bertilsson, L
    et al.
    Universität der Bundeswehr München.
    Potje-Kamloth, K
    Universität der Bundeswehr München.
    Liess, HD
    Universität der Bundeswehr München.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Adsorption of dimethyl methylphosphonate on self-assembled alkanethiolate monolayers1998Inngår i: JOURNAL OF PHYSICAL CHEMISTRY B, ISSN 1089-5647, Vol. 102, nr 7, s. 1260-1269Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The adsorption of dimethyl methylphosphonate (DMMP), a model molecule for sarin, on three different organic interfaces, prepared by solution self-assembly of alkanethiols on gold, was followed by a surface acoustic wave mass sensor and infrared reflection-absorption spectroscopy at room temperature. The surfaces, characterized by the following tail groups (-OH, -CH3, -COOH), show both quantitative and qualitative differences concerning the interaction with DMMP, the acid surface giving rise to the strongest adsorption. Results obtained in UHV, at low temperatures using infrared spectroscopy and temperature-programmed desorption, support this observation and give complementary information about the nature of the interaction. The hydrogen-bond-accepting properties of the P=O part of DMMP and its impact on the design of sensing interfaces based on hydrogen bonding, as well as the use of self-assembled monolayers to study molecular interactions, are discussed.

  • 35.
    Yang, Zhongping
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Kauffmann, JM
    Université Libre de Bruxelles, Belgium.
    Electrochemical characterisation of mixed monolayer assemblies of thiol analogues of cholesterol and fatty acids on gold1997Inngår i: Journal of Electroanalytical Chemistry, ISSN 0022-0728, E-ISSN 1873-2569, Vol. 430, nr 1-2, s. 189-195Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A self-assembled monolayer (SAM) on gold prepared from a binary mixture of a thiol analogue of cholesterol (thiocholesterol, TC) and a functionalised alkanethiol (11-mercaptoundecanoic acid, MUA) has been investigated by voltammetry. The voltammetric results are in agreement with previously reported spectroscopic data and show that the geometric arrangement and composition of the molecules in the mixed monolayer controls the heterogeneous electron transfer process of Fe(CN)(6)(3-) across the assembly. The quantitative description of the influence of TC on the electron transfer rate constant is given through Tafel plots. At the pure MUA SAM electrode, the electron transfer is governed by penetration through the monolayer. The introduction of TC into the SAMs creates defects giving rise to diffusion controlled electron transfer in addition to penetration. By raising the TC content the electron transfer rate constant increases due to diffusion, This behaviour can be explained by a model in which the assembly goes from a penetrative but defect-free film barrier (pure MUA SAM) via a structure with defects in the mixed composition regime to a defect-rich structure consisting of an array of ultramicroelectrodes (pure TC SAM). (C) 1997 Elsevier Science S.A.

  • 36.
    Engquist, Isak
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Lundström, Ingemar
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Parikh, A.N.
    Pennsylvania State University.
    Allara, D. L.
    Pennsylvania State University.
    Infrared characterization of amorphous and polycrystalline D2O ice on controlled wettability self-assembled alkanethiolate monolayers1997Inngår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 106, nr 8, s. 3038-3048Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Infrared reflection-absorption spectroscopy has been used to characterize thin overlayers (1-200 Angstrom) of D2O ice deposited in UHV onto a set of self-assembled alkanethiolate monolayers (SAMs) of controlled wettabilities on gold. The SAMs were prepared from a series of controlled composition, mixed solutions of HS(CH2)(15)CH3 and HS(CH2)(16)OH, making it possible to investigate the whole wettability range from theta approximate to 0 degrees to theta=112 degrees, where theta is the static contact angle with water. Dosing of D2O and infrared measurements were carried out at selected sample temperatures between 82 and 150 K. Experimental spectra of ice overlayers recorded below 100 K on all SAM substrates are in good agreement with simulated reflection-absorption spectra, derived from the optical constants of amorphous ice. This agreement allows accurate film thickness determination. In contrast, lack of correspondence in spectral signature is noted between the spectra of annealed films and simulated polycrystalline (or amorphous) ice spectra. We interpret this discrepancy to suggest that significant substrate-induced differences between thin overlayers and bulk ice persist in the latter case. Spectral indications of ice-substrate interaction are also seen for amorphous ice, and are especially prominent in the case of highly hydrophobic (pure CH3-terminated, theta=112 degrees) substrates. In this case the substrate effect extends up to an average film thickness (150-200 Angstrom) corresponding to similar to 50 ice monolayers, in contrast to highly hydrophilic OH-terminated substrate, where the substrate effects appear to vanish beyond similar to 5 monolayers (15-20 Angstrom average thickness). Annealing of thin ice overlayers (2-3 monolayers) clearly demonstrates a strong correlation between the onset as well as progression of the transition from amorphous to polycrystalline ice and the exact substrate wettability or chemical composition. The data further suggest the existence of metastable intermediate forms, that are neither purely amorphous nor polycrystalline. We discuss these observations in terms of substrate-overlayer interaction. A tentative phase diagram summarizing these results is presented. (C) 1997 American Institute of Physics.

  • 37.
    Bertilsson, Lars
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Interaction of dimethyl methylphosphonate with alkanethiolate monolayers studied by temperature-programmed desorption and infrared spectroscopy1997Inngår i: JOURNAL OF PHYSICAL CHEMISTRY B, ISSN 1089-5647, Vol. 101, nr 31, s. 6021-6027Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The adsorption of dimethyl methylphosphonate (DMMP) on well-defined organic surfaces consisting of self-assembled monolayers (SAMs) of omega-substituted alkanethiolates on gold has been studied. Three different surfaces were examined: one terminated with -OH groups (Au/S-(CH2)(16)-OH), one with -CH3 (Au/S-(CH2)(15)-CH3), and one mixed surface with approximately equal amounts of -OH and -CH3 terminated thiols. Detailed information about the nature and strength of the interaction was gathered by infrared reflection-absorption spectroscopy and temperature-programmed desorption under ultrahigh-vacuum conditions. It is found that the outermost functional groups of the thiol monolayer have a pronounced impact on the interaction with DMMP at low coverage. The -OH surface, allowing for hydrogen bonds with the P=O part of the DMMP molecule, increases the strength of interaction by approximately 3.8 kJ/mol as compared to the -CH3 surface. A preadsorbed layer of D2O leads to stronger interaction on all surfaces. This is explained by additional hydrogen bond formation between free O-D at the ice-vacuum interface and DMMP.

  • 38.
    Engquist, Isak
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Lestelius, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Microscopic wettability of ester- and acetate-terminated self-assembled monolayers1997Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 13, nr 15, s. 4003-4012Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Four different carbonyl-containing self-assembled monolayers (SAMs) of alkanethiolates on gold were studied to assess the impact of the functional group Linked to the carbonyl upon its hydrogen bond accepting capability. These SAMs (HS(CH2)(16)O(C=O)-X,X = CH3, CF3, or C6H5, and HS(CH2)(15)(C=O)OCH3) were thoroughly characterized with contact angle measurements, single wavelength ellipsometry, and infrared reflection-absorption spectroscopy (IRAS) prior to the studies of interaction with D2O. The first three monolayer compounds were introduced by reacting hydroxyl-terminated SAMs (HS(CH2)(16)OH) with either acetyl chloride, trifluoroacetic anhydride, or benzoyl chloride. The behavior of D2O ice on the SAMs was investigated at 100 K with IRAS and temperature programmed desorption (TPD). On all monolayers the D2O molecules were shown to interact with the carbonyl oxygen. The degree of interaction depended upon the termination of the thiol, where the size, structure, and electronegativity of the terminating groups in the molecules comprising the monolayer were found to be important factors. Indications of interaction with the C-O-C oxygen were seen for all compounds, as well as weak interaction between water molecules and the CF3 group of one of the investigated SAMs. Common behavior for all four monolayers with an adsorbed D2O overlayer was a decrease in the number of hydrogen bonds to the substrate when the overlayer was annealed from amorphous ice at 100 K to polycrystalline-like ice at 140 K. The spectral changes accompanying the structural transition were consistent with a change from a mainly flat overlayer to condensed three-dimensional clusters. The bulk-to-surface molecular ratio of adsorbed ice clusters could be assessed by IRAS and correlated to macroscopic wetting properties. Our results infer that microscopic ice clusters on these SAMs qualitatively mimic the shape of macroscopic water drops on the same SAMs. Results of TPD measurements are also consistent with this view.

  • 39.
    Yang, Zhongping
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Wirde, M.
    Uppsala Universitet.
    Kauffmann, J. M.
    Université Libre de Bruxelles, Belgium.
    Gelius, U.
    Uppsala universitet.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Preparation and characterization of mixed monolayer assemblies composed of thiol analogues of cholesterol and fatty acid1997Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 13, nr 12, s. 3210-3218Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mixed self-assembled monolayers provide an attractive model system for investigating the role of different molecules in biological membranes. This paper describes the preparation and characterization of a novel type of mixed monolayer assemblies composed of thiol analogues of cholesterol and fatty acid. The mixed: monolayers are prepared by coadsorbing 11-mercaptoundecanoic acid (MUA) and thiocholesterol(cholest-5-ene-3 beta-thiol, TC) from solution directly onto evaporated gold surfaces. The influence of TC on the molecular composition and conformation in the mixed monolayer is analyzed by using a combination of infrared reflection-absorption spectroscopy (IRAS), X-ray photoelectron spectroscopy (XPS), ellipsometry, contact angle measurement, and cyclic voltammetry. The results indicate that the TC molecules maintain their conformation in the mixed monolayers, whereas the MUA molecules display a significantly more disordered conformation as compared to the MUA molecules in the pure monolayer. Cyclic voltammetry shows that the mixed monolayers are more densely packed and less permeable than the pure TC and MUA monolayers. The kinetics of the coadsorption of TC and MUA from ethanol indicates that adsorption of TC initially is strongly preferred over MUA but that MUA dominates over TC at long coadsorption times. This is because there is a larger energy gain per unit area in forming monolayers with MUA, Further, it is also seen that the number of molecules per unit area changes with the molecular composition, as a consequence of the different sizes of TC and MUA. We present herein a method for calculating the mole fraction of TC on the gold surface, (chi TC), which accounts for this variation. As a consequence of the dissimilar size and shape of the two molecules, the wetting properties of the mixed monolayer are found to be mainly governed by the fractional area of TC, rather than by the molecular composition of TC, (chi TC).

  • 40.
    Liedberg, Bo
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Yang, Zhongping
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Wirde, M.
    Uppsala universitet.
    Gelius, U.
    Uppsala universitet.
    Götz, G.
    University of Ulm, Germany .
    Bäuerle, P.
    University of Ulm, Germany .
    Rummel, R. M.
    University of Tübingen, Germany .
    Ziegler, C.
    University of Tübingen, Germany .
    Göpel, W.
    University of Tübingen, Germany .
    Self-assembly of alpha-functionalized terthiophenes on gold1997Inngår i: JOURNAL OF PHYSICAL CHEMISTRY B, ISSN 1089-5647, Vol. 101, nr 31, s. 5951-5962Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    alpha-Functionalized terthiophenes containing disulfide (-S-T-3-H)(2) and alkanethiol (HS-(CH2)(11)-T-3-H) anchoring groups have been synthesized for direct immobilization onto gold. Monolayer structures of these compounds are prepared by spontaneous assembly from ethanol solutions on evaporated gold substrates and thoroughly characterized by ellipsometry, contact angle goniometry, infrared and X-ray photoelectron spectroscopy, and cyclic voltammetry. The two molecules coordinate to the gold substrate exclusively via the anchoring groups upon formation of gold-thiolate bonds. The kinetics of monolayer formation vary dramatically for the two compounds. The alkanethiol analogue assembles rapidly, within a few minutes, and forms a densely packed and highly organized monolayer, with the alkyl chains in an almost perfect all-trans conformation and the C-alpha-C-alpha axis of the alpha-T-3 units tilted about 14 degrees away from the surface normal. The assembly process is much slower for the disulfide, but an organized monolayer with an average alpha-T-3 chain tilt of about 33 degrees will eventually form when the assembly is allowed to equilibrate with a solution containing the disulfide for at least 1 day. Moreover, the two monolayer assemblies also display a remarkably different electrochemical, behavior. The heterogeneous electron-transfer rate at the disulfide-covered gold substrate is almost indistinguishable from that at bare gold, suggesting that the assembly contains a large number of easily accessible defects. An alternative mechanism for explaining the large electron-transfer rate involving electronic coupling via the conjugated pi-system of the alpha-T-3 units is also proposed. The electrochemical response is significantly reduced for the HS-(CH2)(11)-T-3-H assembly, but another type of defects, the so-called shallow defects originating from sparsely populated areas on the electrode surface, can be identified.

  • 41.
    Engquist, Isak
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    D2O ice on controlled wettability self-assembled alkanethiolate monolayers: Cluster formation and substrate-adsorbate interaction1996Inngår i: JOURNAL OF PHYSICAL CHEMISTRY, ISSN 0022-3654, Vol. 100, nr 51, s. 20089-20096Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Infrared reflection-absorption spectroscopy is used to investigate thin (1-200 Angstrom average thickness) overlayers of D2O ice deposited in ultrahigh vacuum on controlled wettability self-assembled monolayers. The monolayers were derived from mixed solutions of HS(CH2)(15)CH3 and HS(CH2)(16)OH, making it possible to examine the whole range of samples from f(OH) = 0.0 to f(OH) 1.0, where f(OH) denotes the molar fraction of OH-terminated thiols in the preparation solution. This paper focuses on the interaction between the ice and the monolayer. It is shown that water molecules do not penetrate into the monolayer but that two types of interaction with the chain-terminating groups occur: hydrogen bond formation with surface hydroxyls and weak dipole-dipole interaction with surface methyls. For surfaces with f(OH) less than 0.3, the latter interaction causes the free OD mode, normally observed at 2729 cm(-1), to shift to 2704 cm(-1), thereby providing a spectral signature feature whose intensity is directly proportional to the relative area of the ice/monolayer interface. Quantitative analysis of the infrared spectra suggests that ice clusters are essentially flat on surfaces with 0.6 less than f(OH) less than 1.0 and become more droplet-like for decreasing f(OH) below 0.6. On f(OH) = 0.0 surfaces, the microscopic clusters display high contact angles (similar to 120 degrees), and full surface coverage does not occur until the average overlayer thickness is 150-200 Angstrom.

  • 42.
    Yang, Z. P.
    et al.
    Université Libre de Bruxelles, Belgium.
    Engquist, Isak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Kauffmann, J.-M.
    Université Libre de Bruxelles, Belgium.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Thiocholesterol on gold: A nanoporous molecular assembly1996Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 12, nr 7, s. 1704-1707Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The formation of thiocholesterol (TC) monolayers on gold has been studied by ellipsometry, contact angle measurements, infrared spectroscopy, and cyclic voltammetry. Subsequent treatment of the TC assembly with 11-mercaptodeuterioundecanoic acid (MDUA) shows that the average surface coverage is about 65% of that of a self-assembled alkanethiolate monolayer and that it has a large number of molecular defects. These defects exist because of a mismatch between the size and shape of the TC molecule and the pinning distance at the Au(111) crystal lattice. Potential uses of these defect-rich structures are microelectrode arrays for electroanalytical and biosensor applications.

  • 43.
    Engquist, Isak
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Lestelius, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Hydrogen Bond Interaction between Self-Assembled Monolayers and Adsorbed Water Molecules and Its Implications for Cluster Formation1995Inngår i: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 99, nr 39, s. 14198-14200Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Infrared spectroscopy is used to investigate the adsorption of D2O onto self-assembled monolayers of methyl 16-mercaptohexadecanoate on gold. The D2O molecules are shown to interact with the carbonyl oxygens of the monolayer, forming hydrogen bonds and causing a structural rearrangement of the CO2CH3 terminal group. The number of hydrogen bonds decreases as the amorphous-like, essentially flat (two-dimensional) ice overlayer that forms at 100 K changes into polycrystalline-like ice upon annealing at 140 K. This decrease is a consequence of the formation of three-dimensional ice clusters, which leaves a large fraction of the monolayer surface bare.

  • 44.
    Engquist, Isak
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Lundström, Ingemar
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Temperature-programmed desorption and infrared studies of D2O ice on self-assembled alkanethiolate monolayers: influence of substrate wettability1995Inngår i: JOURNAL OF PHYSICAL CHEMISTRY, ISSN 0022-3654, Vol. 99, nr 32, s. 12257-12267Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper examines the relationship between the thermal desorption of thin overlayers of condensed D2O ice and the wettability properties of the supporting substrate surface. Mixed self-assembled monolayers (SAMs) on gold with controlled chemical composition and wettability (-0.4 less than cos theta less than 1.0, where theta represents the static contact angle with water) derived from HS(CH2)(16)OH and HS(CH2)(15)CH3 were used as model surfaces. The D2O ice overlayers were prepared on these substrates by dosing of 0.1-30 langmuirs of D2O in ultrahigh vacuum at 80-120 K and characterized with temperature-programmed desorption (TPD). Infrared reflection-absorption spectroscopy (IRAS) was also used to characterize the structural progressions within the overlayers during the course of the TPD experiments, as well as at selected temperatures before and after annealing of the overlayer structure. The IRAS data show that amorphous-like ice is formed at sufficiently low temperatures (less than or equal to 100 K) on all mixed SAMs, regardless of their wettability. A structural transition of the D2O ice from amorphous-like to polycrystalline-like is observed above 100 K. The exact onset of the transition is strongly dependent on the wettability and varies from about 110 K on the extreme hydrophobic (CH3) substrate to 145-150 K on the hydrophilic (OH) substrate. On the most hydrophilic substrates, the strong hydrogen bond interaction with surface hydroxyls prevents completion of the structural transition before desorption of the D2O overlayer. This type of pinning of the D2O molecules to the substrate surface is most likely responsible for the sharp increase in desorption energy of similar to 0.2 kcal/mol which is seen at cos theta approximate to 0.6, a value defining the hydrophilicity limit above which, for our set of experimental parameters, the transition is no longer completed. The TPD data also support a model of the D2O overlayer as forming clusters of very different shape depending on substrate wettability-flat, two-dimensional clusters on hydrophilic SAMs and dropletlike, three-dimensional clusters on hydrophobic SAMs.

  • 45.
    Tehrani, Payman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Robinson, Nathaniel D.
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Nilsson, David
    Acreo AB, Bredgatan 34, SE-601 21 Norrköping, Sweden.
    Robertsson, Mats
    Acreo AB, Bredgatan 34, SE-601 21 Norrköping, Sweden.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Printable organic temperature logger based on overoxidation front propagation in PEDOT:PSSManuskript (Annet vitenskapelig)
    Abstract [en]

    An electrochemical temperature logger has been realized by using the propagation of overoxidation fronts in stripes of poly(3,4-ethylenedioxythiopehene) blended with poly(styrenesulfonate) (PEDOT:PSS). The over-oxidation front propagation has been characterized and related to the ionic conductivity of polyethylene glycol (PEG) electrolytes. The electrolytes were chosen to have a phase transition in the temperature interval to be monitored, resulting in large conductivity variations and thereby an easily interpreted output. A logger demonstrator has been fabricated and shown to detect a temperature increase and a following temperature decrease. This very simple device is cheap to produce and could be used to monitor the temperature of packages.

  • 46.
    Wang, Xiaodong
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Platt, Duncan
    Acreo AB, Norrköping, Sweden.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Printed low loss capacitors for use in a wireless humidity sensor labelManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    A low loss printed capacitor is achieved by using a screen printable benzocyclobutene-based solution. The dissipation factor is measured to be 0.001 at frequencies around 3 MHz, which is low compared to commercially available dielectric inks with dissipation factors of ~0.05 in the same frequency region. By incorporating low loss printed capacitors with a planar antenna and a printed humidity sensor capacitor, a humidity sensor label which resonates at 3 MHz is demonstrated. The label is fully printed on a flexible substrate pre-patterned with the antenna and the manufacturing process is compatible with low-cost reelto-reel processing technology. The quality factor (Q factor) of the sensor label is enhanced up to about 15 in ambient environment. This allows readout of the sensor response at a distance and through damping materials such as walls in a building.

1 - 46 of 46
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