Solid State Thin Film Solar Cells at Ångström

Johan Lindahl and Sven Englund at work with thin film solar cells in the Microstructure Laboratory (MSL) at Ångström. Photo: Mikael Wallerstedt

Background

Solar cells are becoming a commodity in the landscape of renewable electricity generation at an increasing pace. In Sweden, the start has been slow as compared to Europe and rest of the world, but from 2011 up until 2020, the installed capacity doubled every year. It was from a very low starting level, but nonetheless, it bears a promise for a true market break-through also in Sweden. In 2019, about 120 MW was installed. In the world, over 100 GWp of solar power was installed in 2019, In total, about 5% of the world´s electricity is generated by solar cells and 0.4 % of the electric generation in Sweden.

The introduction of solar cells in the very large scale has been made possible by the reduced prices for both solar cell modules and their systems. The market is dominated by crystalline silicon-based products and thin film solar cells have a market share of less than 5 %. A growing market segment is building integrated solar cells, where thin film solar cells have a large competitive advantage with their uniform and discreet black appearance. Low cost, low weight building elements that can produce electric power to a low cost/kWh is one of the goals of our research. Low weight means that we need to look into other substrate materials than glass, such as steel. Low cost entails that we need to make the solar cell modules highly efficient, since the kWh-cost is dominated by material costs, when produced at large scale.

Aims

Our main goals are affordable and esthetically appealing solar cell modules with efficiencies exceeding 20 %, that are suitable for building integration at large scale. The modules have to be long term stable and mechanically durable. High efficiency is important both for the long term future of the thin film solar cell technology, but also to increase the impact of our research. Here the goal is to regain the small cell world record, which is presently at 23.35 % and held by Solar Frontier in Japan. Our research is considered excellent and world leading and researchers from our division are often invited to give talks at conferences. We are also active in popular science and outreach activities, such as podcasts (Forskarpodden, Marika Edoff 2021), Swedish radio (Vetenskapsradion, Marika Edoff 2021) and Swedish television, e.g. Marika Edoff in Rapport in March 2021.

Approaches

The thin film solar cell research is applied, but with a strong base in fundamental and basic research. Therefore, state-of-the-art analysis methods, such as X-ray based (PES, XRD and XRF), Electron Microscopy (SEM and TEM) as well as a variety of electro-optical characterization are used. Test samples as well as full solar cell and solar cell module devices are produced every day, using our full solar cell baseline in the Ångström clean-room (MSL).

Our results are published in reviewed journals using open access, whenever that is possible. We participate in all major photovoltaic conference to reach out with results among which we consider the European Photovoltaic Solar Energy Conference, the IEEE Photovoltaic Specialists Conference and the two Material Research Society conferences (European and American) to be the most influential.

We collaborate with companies in several projects, among which the most important ones are Evolar AB, Midsummer AB, and AC&CS (Belgium). Our ambition is to be open to collaborations both with companies and with other research groups in Sweden and abroad.

New emerging materials are inorganic perovskites and tin sulfide materials. We are are also combining our CIGS solar cells with perovskite solar cells in tandem devices.

Keywords

Thin Film Solar Cells, Photovoltaics, CIGS, CZTS, co-evaporation, sputtering, high efficiency, tandem, perovskite, tin sulfide, plasmonics

Links and references

https://www.materialvetenskap.uu.se/research/solar-cell-technology/

Research Group

Project leader
Marika Edoff, professor, group leader and leader for CIGS activity

Charlotte Platzer-Björkman, professor, leader for CZTS activity

Tobias Törndahl, associate professor, leader for window layer activity

Carl Hägglund, associate professor, lecturer, Ultra-thin plasmonic solar cell devices (new activity)

Jonathan Scragg, assistant professor

Other project members

Researchers:

Uwe Zimmermann, senior lecturer

Jonathan Scragg, researcher

Jes Larsen, post-doc

Jan Keller, researcher

Nina Shariati Nilsson, researcher

Lars Stolt, adjunct professor

Engineers:

Olivier Donzel-Gargand, Senior Research Engineer

Olof Stolt, project assistant

Amit Patel, Senior Research Engineer (part time)

Björn Kuzavas, Senior Research Engineer (part time)

PhD students:

Sven Englund, defended in 2020

Katharina Rudisch, defended in 2020

Fredrik Larsson, defended in 2020

Nishant Saini (started in 2017)

Faraz Khavari (started in 2016)

Björn Landeke-Wilsmark (started in 2017)

Corrado Comparrotto, started in 2019

Patrick Pearson, started in 2020

Department of Engineering Sciences, Solid State Electronics, Uppsala University

 

Additional funding (apart from StandUp for Energy)

  • The Swedish Energy Agency (Marika Edoff, Tobias Törndahl)
  • The Swedish Strategic Research fund (SSF) (Charlotte Platzer Björkman, Framtidens forskningsledare, and project)
  • The Swedish Science Council (VR) (Jonathan Scragg, Charlotte Platzer Björkman, Carl Hägglund)
  • European Union, Horizon 2020, (ARCIGS- M, Main applicant and Coordinator: Marika Edoff), PECSYS, Custom-Art