Reports now suggest they are capable of efficiencies greater than 20% – a milestone which took other solar cells decades to reach.
But how realistic are these efficiency values? This question is now being asked by national laboratories, with a cluster of research groups finding that the very nature of efficiency testing, as well as the questionable stability of perovskites themselves, is only serving to exaggerate device performance. And unless this stability problem can be solved perovskite devices may never become a viable alternative to silicon solar cells.
He talks to Keith Emery, chief scientist at the National Renewable Energy Laboratory’s (NREL) photovoltaic cell and module performance characterisation group in the US, who says,
All the exciting efficiencies and any energy claims that are associated with [perovskite solar cells] should be taken with a grain of salt…
To solve the stability problem the economics of that material system may go out the door. Until the stability problem is solved, you do not know how much it is going to cost you.’
Martin Green, director of the Centre for Advanced Photovoltaics in Australia, agrees:
Measurement is complicated by the fact that devices are not stable,’ says Green. ‘They display hysteresis in their output.
Cosmos magazine looked at the progress of research into alternatives to silicon in solar cell manufacture last week.
Bill Condie is a science journalist based in Adelaide, Australia.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.