I am interested in the self-organisation of molecules and new materials in thin films for applications in organic optoelectronics, such as solar cells and light-emitting diodes (LEDs).
- molecular materials
- thin film coating from solution
- scanning probe microscopy
- X-ray spectroscopy
- Polymer solar cells
- Perovskite solar cells
- Molecular opto-electronics.
My present prime research focus is on novel materials for photovoltaic applications, including organic and polymer-based solar cells and solution-processed perovskite solar cells. We are interested in the morphology formation and degradation processes of such materials, and their relations to device performance and stability.
The main activities of the research group are in the experimental studies of the formation of phase-separated domain structures in thin films containing conjugated polymers and molecules, such as fullerene derivatives, as they are coated from solution. This work is supported by molecular and thermodynamic modelling. Microscopy and spectroscopy studies carried out in the research group have resulted in contributions to the understanding of how the morphology of such thin films is formed and how that impacts on the solar cell performance.
For halide perovskite and organic solar cell materials, we also study the alignment of energy levels at the interfaces between the photoactive material and the interfacial layers and investigate alternative interfacial layers and transparent electrode materials for the solar cells.
The stability of photovoltaic devices forms another part of our research activities, where we focus especially on the photodegradation of the active layer materials in ambient conditions.
Other topics of interest include blends of conjugated polymers with non-conjugated polymers, self-organisation of monolayers of thiolated conjugated molecular rods on gold surfaces.
The research activities in polymer-based solar cells at Karlstad University started in 2002 with a first grant from the Swedish Research Council (Vetenskapsrådet) and the National Graduate School for Materials Science. Over the years the research continued with further funding from the Swedish Energy Agency (Energimyndigheten) (2007-2010 and 2014-2018), Vetenskapsrådet (2011-2013 and 2016-2019), and the Göran Gustafsson Foundation for Natural Sciences and Medicine (2012 - 2015). The group joined the COST Action StableNextSol (MP1307) with over 60 partners from 26 countries. Ellen Moons coordinates a 5-year project "Mastering Morphology for solution-borne electronics" funded by the the K.A. Wallenberg foundation.
Methods and Collaborations
Atomic force microscopy has been one of the main tools the group has used to characterise the nanosized structures formed in spin-coated thin films of polymer blends. The capabilities of AFM-IR to chemically identify the components in the blend by their infrared vibrational fingerprints, and study their distribution in the thin film with nano-scale resolution, has added an important dimension to the morphology studies of these intermixed molecular layers.
The research activities stretch over the disciplinary borders of materials physics and physical chemistry. The research facilities contain instrumentation for the fabrication and electrical characterization of solar cell devices, as well as equipment for structural and chemical characterization of thin polymer blend films, such as Atomic Force Microscopy (AFM) and FT-IR spectroscopy.
In collaboration with the Jagiellonian University in Krakow, we study compositional depth profiles of the polymer blend thin films by dynamic SIMS. At the synchrotron facility MAX IV in Lund, we are users of Near-edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy and high-resolution X-ray Photoelectron Spectroscopy (XPS) and since recently we use Scanning Transmission X-ray Microscopy (STXM) at the Swiss Light Source (SLS) and the Advanced Light Source in Berkeley in California, USA, to image the composition variations in molecular thin films.
- FYGA25 Experimental problem solving and data analysis, 7.5 ECTS.
- CBAD81 Functional Materials, 7.5 ECTS.
- Diploma work in physics and engineering physics.
In research I collaborate with many national and international research groups.
Some examples are:
- Research project SOLution-borne materials for organic electronic Applications (SOLA), funded by the Knut and Alice Wallenberg Foundation. SOLA is a collaboration between Karlstad University (materials physics och Physical chemistry), Chalmers, Linköping University and Lund University (chemical physics and theoretical chemistry). https://www.kau.se/sola
- COST Action MP1307, StableNextSol, Unraveling Degradation Mechanisms of Organic and Perovskite Solar Cells by Complementary Characterization Techniques, is a European multidisciplinary network of academic och industrial researchers who collaborate about degradation mechanisms in organic solar cells. http://stablenextsol.eu
Since 2011 professor in Materials Physics at Karlstad University, Sweden. Previously employed as Research Scientist at Cambridge Display Technology in Cambridge,UK, and as Research Assistant at University of Cambridge. Post-doc research related to dye-sensitized solar cells at EPFL Lausanne and TU Delft. PhD. from the Weizmann Institute of Science in Rehovot, Israel.
- Hansson, R., Ericsson, L. K.E., Blazinic, V., Holmes, N.P., Dastoor, P., Moons, E., Opportunities and challenges in probing local composition of organic material blends for photovoltaics Journal of Materials Science, Focus Issue: Microstructural Characterization for Emerging Photovoltaic Materials 32, 10 (2017) 1982-1992.
Sudam Chavhan, Hansson, R., Ericsson, L.K.E., Beyer P., Opitz A., Moons, E., Low temperature processed NiO hole transport layers for efficient polymer solar cells, Organic Electronics, Organic Electronics 44 (2017) 59-66.
Ana Sofia Anselmo, Dzwilewski, A., Svensson, K., Moons, E. Light-induced Degradation of the Electronic Structure of PCBM and C60 Thin Films, Chem. Phys. Lett., 652 (2016) 220-224.
Rickard Hansson, Lindqvist, C., Ericsson, L. K. E., Opitz, A., Wang, E., Moons, E., Photodegradation in air of the active layer components in a thiophene-quinoxaline copolymer:fullerene solar cell, Phys. Chem. Chem. Phys., 18 (2016) 11132-11138.
Andreas Opitz, Andreas Wilke, Patrick Amsalem, Martin Oehzelt, Ralf-Peter Blum, Jürgen Rabe, Toshiko Mizokuro, Ulrich Hoermann, Rickard Hansson, Ellen Moons, and Norbert Koch, Organic heterojunctions: Contact-induced molecular reorientation, interface states, and charge re-distribution, Scientific Reports, 6 (2016) 21291
Rickard Hansson, Ericsson, L.K.E., Holmes, N.P., Rysz, J., Opitz, A., Campoy-Quiles M., Wang, E., Barr, M.G., Kilcoyne, A.L.D., Zhou, X., Dastoor, P., Moons, E., Vertical and lateral morphology effects on solar cell performance for a thiophene-quinoxaline copolymer:PC70BM blend, J. Mater. Chem. A 3 (2015), 6970-6979.
Jasper Michels, Moons, E., Simulation of Surface-Directed Phase Separation in a Solution-Processed Polymer/PCBM Blend, Macromolecules 46, 12 (2013) p. 8693-8701.
Iulia Brumboiu, Anselmo, A.S., Brena, B., Dzwilewski, A., Svensson, K., Moons, E., Near-edge X-ray Absorption Fine Structure Study of the C60-derivative PCBM, Chemical Physics letters 568–569 (2013) p. 130–134.
Cecilia M. Björström Svanström, Rysz, J., Bernasik, A., Budkowski, A., Zhang, F., Benson-Smith, J. J., Inganäs, O., Andersson, M. R., Magnusson, K. O., Nelson, J., Moons, E., Device performance of APFO-3/PCBM solar cells with controlled morphology, Adv. Mater. 21, 43 (2009), p.4398-4403.
Somsakul Watcharinyanon, Puglia, C., Göthelid, E., Jan-E. Bäckvall, J.-E., Moons, E., and Johansson, L. S. O., Molecular orientation of thiol-derivatized tetraphenylporphyrin on gold studied by XPS and NEXAFS, Surface Science 603, 7 (2009), p.1026-33.
Nilsson, S., Bernasik, A., Budkowski, A., Moons, E., Morphology and phase segregation of spin-casted films of polyfluorene/PCBM blends, Macromolecules 40, 23 (2007), p. 8291-8301
Zhang, F., Jespersen, K.G., Björström, C., Svensson, M., Andersson, M.R., Sundström, V., Magnusson, K.O., Moons E., Yartsev, A., and Inganäs, O., Influence of solvent mixing on the morphology and performance of solar cells based on polyfluorene copolymer/fullerene blends, Adv. Funct. Mater., 16, 5, (2006) p. 667-674
Cecilia M. Björström, Bernasik, A., Rysz, J., Budkowski, A., Nilsson, S., Svensson, M., Andersson, M.R., Magnusson, K.O., and Moons, E., Multilayer formation in spin-coated thin films of low-bandgap polyfluorene:PCBM blends, J. Phys.: Condens. Matter, 17 (2005), L529–L534.
Morteani, A.C., Dhoot, A.S., Kim, J.-S., Silva, C., Greenham, N.C., Friend, R.H., Murphy, C., Moons, E., Ciná, S., Burroughes, J., Barrier-Free Electron-Hole Capture in Polymer Blend Heterojunction Light-Emitting Diodes, Adv. Mater. 15, 20 (2003) p. 1708-1712
Ellen Moons, Conjugated Polymer Blends: Linking Film Morphology to Performance of Light Emitting Diodes and Photodiodes, J. Phys.: Condens. Matter 14, 47 (2002) p. 12235-12260.
Lukas Schmidt-Mende, Fechtenkötter, A., Müllen, K., Moons, E., Friend, R.H., MacKenzie, J.D., Self-organised Discotic Liquid Crystals for High Efficiency Organic Photovoltaics, Science 293 (2001) p. 1119-1122.