For decades, slabs of crystalline silicon have dominated the solar industry. Other materials that can be layered in thin films, such as copper indium gallium selenide (CIGS) and cadmium telluride (CdTe), have captured less than 5% of the market, because it’s hard to make them as efficient or cheap as conventional solar panels. Perovskites could be a different story. They should be cheaper to make and seem impressively efficient at converting sunlight into electricity — in the laboratory, at least.
Companies say they are close to commercializing cheap perovskite films that could disrupt solar power — but are they too optimistic?