Cheap laser hope from light-emitting perovskite solar cell material

Commercial silicon-based solar cells operate at about 20 per cent efficiency for converting the Sun’s rays into electrical energy and it has taken over 20 years to achieve that rate of efficiency.

An Oxford research team led by Prof Henry Snaith recently pioneered a relatively new type of solar cell based on a perovskite material.

Perovskite solar cells already lie a fraction behind commercial silicon, having reached 17 per cent efficiency after two years of research, thereby transforming prospects for cheap large-area solar energy generation.

Now, researchers from Prof Sir Richard Friend’s group at Cambridge’s Cavendish Laboratory, working with Snaith’s Oxford group, have demonstrated that perovskite solar cells excel at emitting light.

The new findings, recently published online in the Journal of Physical Chemistry Letters, show that these cells can also produce cheap lasers.

By sandwiching a thin layer of the lead halide perovskite between two mirrors, the team is said to have produced an optically driven laser which proves these cells show efficient luminescence with up to 70 per cent of absorbed light re-emitted.