Commercial silicon-based solar cells – such as those seen on the roofs of houses across the country – operate at about 20% efficiency for converting the Sun’s rays into electrical energy. It’s taken over 20 years to achieve that rate of efficiency.
Perovskite solar cells, the source of huge excitement in the research community, already lie just a fraction behind commercial silicon, having reached a remarkable 17% efficiency after a mere two years of research.
[R]esearchers have demonstrated that perovskite cells excel not just at absorbing light but also at emitting it.
By sandwiching a thin layer of the lead halide perovskite between two mirrors, the team produced an optically driven laser which proves these cells “show very efficient luminescence” – with up to 70% of absorbed light re-emitted.