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BETA
Andersson, Lars Mattias
Alternative names
Publications (10 of 32) Show all publications
Bao, Q., Fabiano, S., Andersson, M., Braun, S., Sun, Z., Crispin, X., . . . Fahlman, M. (2016). Energy Level Bending in Ultrathin Polymer Layers Obtained through Langmuir-Shafer Deposition. Advanced Functional Materials, 26(7), 1077-1084
Open this publication in new window or tab >>Energy Level Bending in Ultrathin Polymer Layers Obtained through Langmuir-Shafer Deposition
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2016 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 26, no 7, p. 1077-1084Article in journal (Refereed) Published
Abstract [en]

The semiconductor-electrode interface impacts the function and the performance of (opto) electronic devices. For printed organic electronics the electrode surface is not atomically clean leading to weakly interacting interfaces. As a result, solution-processed organic ultrathin films on electrodes typically form islands due to dewetting. It has therefore been utterly difficult to achieve homogenous ultrathin conjugated polymer films. This has made the investigation of the correct energetics of the conjugated polymer-electrode interface impossible. Also, this has hampered the development of devices including ultrathin conjugated polymer layers. Here, LangmuirShafer-manufactured homogenous mono-and multilayers of semiconducting polymers on metal electrodes are reported and the energy level bending using photoelectron spectroscopy is tracked. The amorphous films display an abrupt energy level bending that does not extend beyond the first monolayer. These findings provide new insights of the energetics of the polymer-electrode interface and opens up for new high-performing devices based on ultrathin semiconducting polymers.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2016
National Category
Physical Sciences Electrical Engineering, Electronic Engineering, Information Engineering Biological Sciences
Identifiers
urn:nbn:se:liu:diva-126253 (URN)10.1002/adfm.201504729 (DOI)000371079300010 ()
Note

Funding Agencies|EU project SUNFLOWER of FP7 cooperation programme [287594]; Swedish Research Council [2013-4022]; Goran Gustafsson Foundation for Research in Natural Sciences and Medicine; Swedish Research Council Linnaeus grant LiLi-NFM; Advanced Functional Materials Center at Linkoping University

Available from: 2016-03-21 Created: 2016-03-21 Last updated: 2017-11-30
Gao, F., Himmelberger, S., Andersson, M., Hanifi, D., Xia, Y., Zhang, S., . . . Inganäs, O. (2015). The Effect of Processing Additives on Energetic Disorder in Highly Efficient Organic Photovoltaics: A Case Study on PBDTTT-C-T:PC71BM. Advanced Materials, 27(26), 3868-3873
Open this publication in new window or tab >>The Effect of Processing Additives on Energetic Disorder in Highly Efficient Organic Photovoltaics: A Case Study on PBDTTT-C-T:PC71BM
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2015 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 27, no 26, p. 3868-3873Article in journal (Refereed) Published
Abstract [en]

Energetic disorder, an important parameter affecting the performance of organic photovoltaics, is significantly decreased upon the addition of processing additives in a highly efficient benzodithiophene-based copolymer blend (PBDTTT-C-T:PC71BM). Wide-angle and small-angle X-ray scattering measurements suggest that the origin of this reduced energetic disorder is due to increased aggregation and a larger average fullerene domain size together with purer phases.

Place, publisher, year, edition, pages
Wiley-VCH Verlag, 2015
National Category
Biological Sciences
Identifiers
urn:nbn:se:liu:diva-120340 (URN)10.1002/adma.201405913 (DOI)000357688900002 ()26016473 (PubMedID)
Note

Funding Agencies|Swedish Research Council (VR); European Commission Marie Sklodowska-Curie actions; Swedish Energy Agency; Knut and Alice Wallenberg foundation (KAW)

Available from: 2015-07-31 Created: 2015-07-31 Last updated: 2017-12-04
Andersson, M., Hedstrom, S. & Persson, P. (2013). Conformation sensitive charge transport in conjugated polymers. Applied Physics Letters, 103(21), 213303
Open this publication in new window or tab >>Conformation sensitive charge transport in conjugated polymers
2013 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 103, no 21, p. 213303-Article in journal (Refereed) Published
Abstract [en]

Temperature dependent charge carrier mobility measurements using field effect transistors and density functional theory calculations are combined to show how the conformation dependent frontier orbital delocalization influences the hole-and electron mobilities in a donor-acceptor based polymer. A conformationally sensitive lowest unoccupied molecular orbital results in an electron mobility that decreases with increasing temperature above room temperature, while a conformationally stable highest occupied molecular orbital is consistent with a conventional hole mobility behavior and also proposed to be one of the reasons for why the material works well as a hole transporter in amorphous bulk heterojunction solar cells.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2013
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-102780 (URN)10.1063/1.4832075 (DOI)000327590400078 ()
Note

Funding Agencies|Swedish Energy Agency||Swedish Research Council||

Available from: 2014-01-07 Created: 2013-12-26 Last updated: 2017-12-06
Müller, C., Andersson, M., Pena-Rodriguez, O., Garriga, M., Inganäs, O. & Campoy-Quiles, M. (2013). Determination of Thermal Transition Depth Profiles in Polymer Semiconductor Films with Ellipsometry. Macromolecules, 46(18), 7325-7331
Open this publication in new window or tab >>Determination of Thermal Transition Depth Profiles in Polymer Semiconductor Films with Ellipsometry
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2013 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 46, no 18, p. 7325-7331Article in journal (Refereed) Published
Abstract [en]

Geometric confinement and interface effects can significantly alter the thermodynamic properties of thin polymer films. Phase transition temperatures have been shown to strongly depend on film thickness below a critical thickness threshold. It has been suggested that this behavior is due to an interface-induced continuous variation in phase transition 200 temperatures throughout the depth of the films. Here we employ variable-temperature spectroscopic ellipsometry to demonstrate the existence of these depth profiles. We examine four different polymer semiconductors that are of interest for organic light-emitting diodes, solar cells, and field-effect transistors. In contrast to insulating polymers, these light-absorbing materials provide detailed information about structural changes as a function of depth due to wavelength-dependent attenuation. This concept enables us to investigate a broad range of thermodynamic processes including the glass transition, crystallization as well as crystalline and liquid-crystalline melting. In general, for the here investigated systems, higher transition temperatures are found at the free surface. Finally, the deduced profiles are used to predict the thickness dependence of the mean phase transition temperature.

Place, publisher, year, edition, pages
American Chemical Society, 2013
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-104302 (URN)10.1021/ma400871u (DOI)000330145700021 ()
Available from: 2014-02-17 Created: 2014-02-14 Last updated: 2017-12-06
Tang, Z., Andersson, M., George, Z., Vandewal, K., Tvingstedt, K., Heriksson, P., . . . Inganäs, O. (2012). Interlayer for Modified Cathode in Highly Efficient Inverted ITO-Free Organic Solar Cells. Advanced Materials, 24(4), 554-558
Open this publication in new window or tab >>Interlayer for Modified Cathode in Highly Efficient Inverted ITO-Free Organic Solar Cells
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2012 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 24, no 4, p. 554-558Article in journal (Refereed) Published
Abstract [en]

Inverted polymer solar cells with a bottom metal cathode modified by a conjugated polymer interlayer show considerable improvement of photocurrent and fill factor, which is due to hole blocking at the interlayer, and a modified surface energy which affects the nanostructure in the TQ1/[70]PCBM blend.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2012
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-74183 (URN)10.1002/adma.201104579 (DOI)
Available from: 2012-01-20 Created: 2012-01-20 Last updated: 2017-12-08
Andersson, M., Hsu, Y.-T., Vandewal, K., Sieval, A. B., Andersson, M. R. & Inganäs, O. (2012). Mixed C60/C70 based fullerene acceptors in polymer bulk-heterojunction solar cells. Organic electronics, 13(12), 2856-2864
Open this publication in new window or tab >>Mixed C60/C70 based fullerene acceptors in polymer bulk-heterojunction solar cells
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2012 (English)In: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 13, no 12, p. 2856-2864Article in journal (Refereed) Published
Abstract [en]

Different mixtures of identically substituted C60 and C70 based fullerens have been used as acceptors in three polymer: fullerene systems that strongly express various performance limiting aspects of bulk heterojunction solar cells. Results are correlated with, and discussed in terms of e.g. morphology, charge separation, and charge transport. In these systems, there appears to be no relevant differences in either mobility or energy level positions between the identically substituted C60 and C70 based fullerenes tested. Examples of how fullerene mixtures influence the nano-morphology of the active layer are given. An upper limit to the open circuit voltage that can be obtained with fullerenes is also suggested.

Place, publisher, year, edition, pages
Elsevier, 2012
Keywords
Bulk-heterojunction solar cell; Fullerene; Polymer
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-87210 (URN)10.1016/j.orgel.2012.08.028 (DOI)000311681600012 ()
Available from: 2013-01-14 Created: 2013-01-14 Last updated: 2017-12-06
Tang, Z., George, Z., Ma, Z., Bergqvist, J., Tvingstedt, K., Vandewal, K., . . . Inganäs, O. (2012). Semi-Transparent Tandem Organic Solar Cells with 90% Internal Quantum Efficiency. ADVANCED ENERGY MATERIALS, 2(12), 1467-1476
Open this publication in new window or tab >>Semi-Transparent Tandem Organic Solar Cells with 90% Internal Quantum Efficiency
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2012 (English)In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 2, no 12, p. 1467-1476Article in journal (Refereed) Published
Abstract [en]

Semi-transparent (ST) organic solar cells with potential application as power generating windows are studied. The main challenge is to find proper transparent electrodes with desired electrical and optical properties. In this work, this is addressed by employing an amphiphilic conjugated polymer PFPA-1 modified ITO coated glass substrate as the ohmic electron-collecting cathode and PEDOT:PSS PH1000 as the hole-collecting anode. For active layers based on different donor polymers, considerably lower reflection and parasitic absorption are found in the ST solar cells as compared to solar cells in the standard geometry with an ITO/PEDOT:PSS anode and a LiF/Al cathode. The ST solar cells have remarkably high internal quantum efficiency at short circuit condition (similar to 90%) and high transmittance (similar to 50%). Hence, efficient ST tandem solar cells with enhanced power conversion efficiency (PCE) compared to a single ST solar cell can be constructed by connecting the stacked two ST sub-cells in parallel. The total loss of photons by reflection, parasitic absorption and transmission in the ST tandem solar cell can be smaller than the loss in a standard solar cell based on the same active materials. We demonstrate this by stacking five separately prepared ST cells on top of each other, to obtain a higher photocurrent than in an optimized standard solar cell.

Place, publisher, year, edition, pages
Wiley-VCH Verlag Berlin, 2012
Keywords
polymer solar cells, semi-transparent solar cells, interface, conjugated polymers, tandem solar cells
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-86894 (URN)10.1002/aenm.201200204 (DOI)000312035800008 ()
Note

Funding Agencies|Swedish Energy Agency||Swedish Research Council||Advanced Functional Materials initiative at Linkoping University||Knut and Alice Wallenberg Foundation (KAW)||KAW||VINNOVA||

Available from: 2013-01-07 Created: 2013-01-07 Last updated: 2015-05-29
Andersson, L. M. (2011). Charge transport and energetic disorder in polymer: fullerene blends. ORGANIC ELECTRONICS, 12(2), 300-305
Open this publication in new window or tab >>Charge transport and energetic disorder in polymer: fullerene blends
2011 (English)In: ORGANIC ELECTRONICS, ISSN 1566-1199, Vol. 12, no 2, p. 300-305Article in journal (Refereed) Published
Abstract [en]

Mobility versus temperature measurements on two different polymer: fullerene blends intended for solar cell applications have been evaluated in terms of the energetic disorder and how this varies with stoichiometry. The charge transport is shown to be confined to the intended phases in both cases, but with fundamentally different interaction properties. In one case the energetic disorder is a function of stoichiometry for the hole transport, while it is constant and equal to that of the pure fullerene for electrons, and in the other case it is the hole transport that has a stoichiometry independent energetic disorder. Transport site dilution is argued to be present in the fixed energetic disorder system and this is offered as a partial explanation to molecular weight dependent currents in solar cells. Determination of the glass transition temperature through the use of field effect transistors is also demonstrated.

Place, publisher, year, edition, pages
Elsevier Science B.V., Amsterdam., 2011
Keywords
Polymer, Fullerene, Electrical transport, Mobility, Temperature dependence, Gaussian disorder model
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-66124 (URN)10.1016/j.orgel.2010.11.007 (DOI)000286462600013 ()
Available from: 2011-03-04 Created: 2011-03-04 Last updated: 2011-03-04
O Reese, M., Gevorgyan, S. A., Jorgensen, M., Bundgaard, E., Kurtz, S. R., Ginley, D. S., . . . C Krebs, F. (2011). Consensus stability testing protocols for organic photovoltaic materials and devices. SOLAR ENERGY MATERIALS AND SOLAR CELLS, 95(5), 1253-1267
Open this publication in new window or tab >>Consensus stability testing protocols for organic photovoltaic materials and devices
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2011 (English)In: SOLAR ENERGY MATERIALS AND SOLAR CELLS, ISSN 0927-0248, Vol. 95, no 5, p. 1253-1267Article in journal (Refereed) Published
Abstract [en]

Procedures for testing organic solar cell devices and modules with respect to stability and operational lifetime are described. The descriptions represent a consensus of the discussion and conclusions reached during the first 3 years of the international summit on OPV stability (ISOS). The procedures include directions for shelf life testing, outdoor testing, laboratory weathering testing and thermal cycling testing, as well as guidelines for reporting data. These procedures are not meant to be qualification tests, but rather generally agreed test conditions and practices to allow ready comparison between laboratories and to help improving the reliability of reported values. Failure mechanisms and detailed degradation mechanisms are not covered in this report.

Place, publisher, year, edition, pages
Elsevier Science B.V., Amsterdam., 2011
Keywords
Stability, Lifetime, Testing, Protocol, Reporting
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-68680 (URN)10.1016/j.solmat.2011.01.036 (DOI)000290359200003 ()
Available from: 2011-05-27 Created: 2011-05-27 Last updated: 2011-05-30
Andersson, M., Mueller, C., Badada, B. H., Zhang, F., Wuerful, U. & Inganäs, O. (2011). Mobility and fill factor correlation in geminate recombination limited solar cells. Journal of Applied Physics, 110(2), 024509
Open this publication in new window or tab >>Mobility and fill factor correlation in geminate recombination limited solar cells
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2011 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 110, no 2, p. 024509-Article in journal (Refereed) Published
Abstract [en]

Empirical data for the fill factor as a function of charge carrier mobility for two different polymer: fullerene systems is presented and analyzed. The results indicate that charge extraction depth limitations and space charge effects are inconsistent with the observed behavior, and the decrease in the fill factor is, instead, attributed to the field-dependent charge separation and geminate recombination. A solar cell photocurrent limited by the Onsager-Braun charge transfer exciton dissociation is shown to be able to accommodate the experimental observations. Charge dissociation limited solar cells always benefit from increased mobilities, and the negative contribution from the reduced charge separation is shown to be much more important for the fill factor in these material systems than any adverse effects from charge carrier extraction depth limitations or space charge effects due to unbalanced mobilities. The logarithmic dependence of the fill factor on the mobility for such a process is also shown to imply that simply increasing the mobilities is an impractical way to reach very high fill factors under these conditions since unrealistically high mobilities are required. A more controlled morphology is, instead, argued to be necessary for high performance.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2011
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-70757 (URN)10.1063/1.3609079 (DOI)000293476300104 ()
Note
|Available from: 2011-09-16 Created: 2011-09-16 Last updated: 2017-12-08
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