Fluorinated ligands stabilise perovskite solar cells

A new type of fluorinated ammonium ligand stabilises the surface of lead halide perovskites. The work marks a key step in understanding how to increase the efficiency and durability of perovskite solar cells.

One of the main causes of degradation to perovskite solar cells is ion mobility at surface defects. Such defects can also reduce efficiency by providing sites for electron–hole recombination. Most perovskite solar cells therefore incorporate a coating to ‘passivate’ the defects.