More and more people are turning to solar energy. Currently, silicon solar panels are the standard option, but the emergence of the relatively new perovskite solar panels promises significant improvements in efficiency. Bas van Gorkom, recently promoted at Eindhoven University of Technology (TU/e), has developed a special measurement technique that can further optimise perovskite solar cells.
Why you need to know this:
We are generating more and more power. Meanwhile, we need to make sure we do so as efficiently as possible. Bas van Gorkom’s work contributes to that.
With the growing demand for renewable energy, scientists are looking for ways to improve solar panels. Traditional silicon solar cells are nearing their physical limit, with an efficiency of about 23 per cent. Perovskite solar cells, made from a semiconductor salt, are not yet on the market, but promise a more efficient alternative for the future.
Improving perovskite solar cells
Perovskite solar cells are currently still subject to processes that adversely affect efficiency. This is because some of the light particles absorbed by the solar cell are not converted usable power. Van Gorkom has focused on measuring these processes in recent years. Last year, the TU/e researcher successfully defended his thesis. Van Gorkom’s work was part of ARC-CBBC, a consortium of Dutch companies and universities.
Highly sensitive measurement
“The measurement technique I have been working on is essentially a very sensitive current measurement, which maps the crystal lattice of perovskite in detail. The technique measures exactly how many photons are converted into electrons. Or, in other words, how much current is generated. However, we are dealing here with loss processes, with so-called trap-assisted recombination, where charges are trapped in the solar cell material. You can compare this to a small trap. This prevents solar cells from achieving optimum efficiency.” The method can detect even the smallest irregularities, with one in a hundred million light particles being converted into an electron.
Van Gorkom had to carry out his research under special conditions, in the dark. “I measure a current so small that it is close to noise,” he explains. Detecting these weak signals requires a stable environment, free of disturbing external factors.” Fortunately, the room had good air conditioning, which made it very pleasant in summer. “But when experiments lasted whole days, it was nice to see some daylight again,” the researcher says with a laugh.
He did it all for a good cause. “If you know what traps are in the material, and where, then it becomes easier to come up with solutions to eventually remove those traps from your material.” In other words: This insight is essential for improving the performance of solar cells and could eventually contribute significantly to a large-scale rollout of this promising technology.
A promising future
Gorkom’s role in research is over. He has since changed direction and now works as a consultant at Innovencio, where he advises and supports companies on sustainability. “Totally different, then,” he says with a smile. “So I am still in the sustainability corner, though. It’s a subject that will definitely continue to play a big role in my work.”
“The measuring equipment is still just there,” he notes, “so successors can build on my research.”