Report from the Zaban Laboratory: Perovskite and the Secret of Photovoltaic Success
Silicon-based solar panels are facing some serious competition. That’s because perovskite – an inexpensive, versatile compound with superior optical and electronic properties – is increasingly seen as the “go-to” material for the next generation of photovoltaic technologies. In the laboratory of Prof. Arie Zaban – BINA’s founding director – researchers are hard at work, designing the next generation of perovskite-based solar cells. This practically-oriented endeavor is guided by basic scientific research that, for the first time, has revealed the light-activated structural dynamics that makes perovskites unique.
Applying perovskites to solar cells was a game-changer. This is because, while the demonstrated efficiency of silicon-based photovoltaics hovers around 25 percent – even after decades of industrial investment – perovskite materials are not far behind, with its current 20.1 percent efficiency representing a five-fold improvement over what was achieved just three years ago. According to the Zaban team, this steady improvement indicates that materials researchers have a good chance, in the near future, of achieving better performance than is possible with silicon-based cells.
In a recent achievement published in Physical Chemistry Letters, members of the Zaban lab – along with BINA faculty member Dr. Yaakov Tischler – used Raman spectroscopy and XRD to demonstrate the existence of photo-induced structural changes in the perovskite structure that contribute to solar cell performance.
In another publication that appeared in the same journal, the team clarified the nature of these structural changes. Using photoconductivity analysis of perovskite films, they observed gradual and reversible changes in the photo response. Too slow to be attributed to electronic processes, there was only one other possibility: that the light itself was affecting the films’ molecular structure.
The researchers observed how, under working conditions, perovskite solar cell performance varies according both to the light intensity and the film deposition characteristics. The findings may explain the time it takes for these cells to reach maximum power upon illumination. On a more fundamental level, these observations help characterize the unique properties which may be the secret of perovskites’ photovoltaic success.
The Zaban team is continuing to examine various cell configurations and architectures, in order to make the most of perovskite’s energy-producing potential. Having begun its research on perovskite materials only 2.5 years ago, team members are pleased to have already made a contribution. Theoretically, they believe, perovskite should eventually be able to surpass silicon in terms of performance – making the large-scale use of solar power more practical and much, much cheaper.