Twist's Review #4 - Next Step for Solar Cells?

Article : A new kind of solar cell is coming: is it the future of green energy?

Solar cells, a well known tool to harvest energy from sunlight and one of the leading solutions for renewable energy, is continuously developing in efficiency, stability and cost. Currently much of the commercial solar cells are silicon based, which have an efficiency of about 22%-24% with the promise of degradation only to 80% after 25 years.

Further developments with solar cells are concerns the material that will be used in the cells itself. Recently perovskites have been getting very popular, especially in the PV community. Perovskites are essentially materials with a crystal structure of ABX3 where A and B are cations and X is an anion, commonly being oxygen. They are usually made of materials that are cheap and abundant, thus attracting a lot of attention not just within the PV community but also in others, mainly photonic/optoelectronic related.

This article describes the current situation with perovskite based solar cells, specifically tandem cells where perovskites are layered on top of silicon which offer better efficiency. The article itself mentions that there are 2 key challenges being the cell stability and the fact that silicon cells are already competitive enough to reach the 2060 capacity target of 75 TW with solar cells. There are though also other concerns mentioned in the article such as the impractical manufacture of current and previous solar cells that incorporate perovskite and the size at which record-breaking lab-made cells have been made at (too small for practical usage and clear commercial performance testing).

Now though, there are many parties which are working in tandem - pun absolutely intended - at different parts of the world including Oxford PV from the UK, Qcells from South Korea, LONGi from China and also academic-industry coop projects such as PEPPERONI in Europe and ADDEPT in the USA. The aim is along the lines of around 26%-28% efficiency and performance degradation of less than 1% per year.

[1] M. Peplow, “A new kind of solar cell is coming: is it the future of green energy?,” Nature, vol. 623, no. 7989, pp. 902–905, Nov. 2023, doi: 10.1038/d41586-023-03714-y.

So this article was an interesting read as I was always interested in learning more about perovskites and their application in solar cells but I never really got to doing it. This article kind of sums up most of the research and industry progress for perovskites and also the future plans and outlook for solar cells. It’s quite exciting to see improvements with solar cells as obviously silicon based solar cell efficiency is currently plateauing and solutions needs to be found.

Some other interesting headlines/papers I came across describe perovskite only solar cells where multiple different perovskites are stacked on top of each other, up to four layers if I recall correctly. Now while that sounds really cool, there is still the obvious challenge of stability. If one perovskite layer already proved challenging to be made stable, what about four? Anyways, this article was nice read, please the article for more details regarding numbers and other information you might want to know of.