“It’s very fulfilling to have a career in physics.” – Interview with Prof. Safa Shoaee

Physicist Prof. Safa Shoaee is one of the world’s most renowned researchers in the field of organic solar cells. After studying in London and Queensland, she received the Sofja Kovalevskaja Prize in 2016 when she began her work at the University of Potsdam and has since been conducting research in the Potsdam Science Park. With Dieter Neher, professor of soft matter physics, she was able to produce the world’s most efficient 1 cm2 organic solar cells here. In this conversation, we talk about green technologies and the way to make a career in physics as a woman.

Prof. Shoaee, you have been working on organic materials for solar cells for about 13 years. What drove you to devote yourself to this research topic?

What drove me to start this is actually something I watched on TV when I was very young. It was about an architect who had an impressive house somewhere very sunny and they emphasised that almost everything there was powered by solar cells. When I saw that I thought: I definitely want that house and then I can run everything with solar technology (laughs).

How would you explain your research to people outside the field?

I try to understand the physical processes in organic semiconductors, organic substances with electrical conductivity, and organic materials. My focus is on understanding these systems for specific optoelectronic applications. One such application can be a solar cell, for instance, or, sensors and many other things. Research on this began several decades ago, when physicists had started to take an interest in coloured molecules in organic conductors.

Here is what I find very interesting: almost anything that nature makes that is colourful, is colourful for a reason. And a lot of time it is colourful to absorb sunlight. So, what we are essentially doing in our research is to mimic nature to make organic materials with specific colours and understand the physical processes behind these materials to develop a solar cell or other optoelectronic devices.

In your view, what is the advantage of organic materials?

Organic materials have the potential to be a lighter version of silicon semiconductors. However, organic solar cells will prove far more versatile wherever flexibility, (lighter) weight and colour are important. In addition, the dominant material used in today’s solar cells, crystalline silicon, doesn’t perform as well under lamps as it does beneath the direct sunlight. Nonetheless, traditional silicon solar cells will continue to be important for the predominantly commercial electricity generation. When they come into play, silicon has major disadvantages and organic semiconductors can make a large contribution in household appliances and internet of things. When they function optimally, they can also be produced far more cheaply.

Organic materials – now that sounds a bit abstract. What are these materials made of and how are they produced?

Organic materials consist mainly of carbon and hydrogen. Chemically speaking, this means that polymers, i.e. larger molecules, are synthesised from certain small molecules, the so-called monomers. This is a highly complex process that we cannot perform ourselves. There are companies and research institutes that specialise in synthesising these materials. My job is not to produce them, but to understand how organic semiconductors work, how their molecules structured is related to their properties.

Organic semiconductors absorb light better, but they generate less energy and are less stable. Do you see a chance for them to reach a wide market?

Organic solar cells are not yet ready for the market. Nevertheless, we have had breakthroughs in research, and we have reached new milestones in terms of efficiency, which is currently above 18 percent. We now know the potential, however, and can assess as to what is possible in the next few years. Commercial use is just around the corner. I see a lot of potential for the market.

What is the current status of your research work? What would you like to achieve in the next five years?

I am very happy with what we have achieved so far. The infrastructure we have is absolutely fantastic. I work with Diether Neher, who has been doing research here for over 20 years. With my laboratory and his premises, we have enough laboratory space for our research. In this collaboration, in 2019 we produced the world’s most efficient 1 cm2, organic solar cell. It was certified 2019 and held the record in 2020 as well. I intend to forge ahead with this in the next few years: to continue to increase efficiency through understanding the physics behind the materials.

You studied in London and did research at the University of Queensland (Australia). You have been at the University of Potsdam since 2016. What brought you here to the Potsdam Science Park?

There were two reasons. Firstly, I had the honour of being awarded the Sofja Kovalevskaja Award. The award opened up a great opportunity for me to set up my own working group with a very generous funding. The award also included a stay in Germany. Then came the second reason: Prof. Diether Neher. For 20 years, he has established himself with his research in the field of solar cells. He is really highly recognised worldwide. Even in Queensland, he was popular. I wanted to learn new things from him, to combine his research with mine and thus raise our understanding to a new level.

How international is research at the Potsdam Science Park compared to other countries and cities?

The Potsdam Science Park is very international. That actually surprised me. Of course, it’s not as international as in London or Queensland, but that’s probably also because English is the national language there anyway.

What is your impression: Is research done differently here than in other countries?

That is indeed the case. The Germans do research differently. They focus a lot on one fundamental question and go into more depth in their research than the experience I had at ICL (Imperial College London, Ed.) or UQ (University of Queensland, Ed.). Another uniqueness here is, building setups as opposed to buying the readily available setup! This is a big contrast.

The proportion of women in scientific disciplines and in leadership positions is often still low. Do you see a change here? What advice would you give to young female scientists?

As an Iranian woman, I see this differently. In Iran very interestingly, more women study physics (and maths) than men. For me, it is important that something changes in the perception of girls from young age. Girls are just as capable as boys at physics. There is no physics gene in boys that is missing in girls. It’s all about society and environment both in terms of what girls are told when growing up but also the society’s view and expectation of/ from a woman.

Women shouldn’t think that they can’t study something. What I’ve realised in my life is that if you want something, you can work to get it. And it’s very fulfilling to have a career in physics (or anything one is passionate about). There’s no reason why women shouldn’t pursue it. Holding a leadership position, however, is different to studying. and for that we need more fundamental changes in the society.

Prof. Shoaee, thank you for the interview.

This blog and the projects of Standortmanagement Golm GmbH in the Potsdam Science Park are funded by the European Regional Development Fund (ERDF) and the State of Brandenburg.