“…Amongst them, organic–inorganic hybrid perovskites, such as organo‐lead halide perovskites (with general structure APbX 3, where A represents a small molecule organic amine, and X is a halide) can be prepared at low cost and show useful optical properties, as well as superior electrical conductivity 4, 7, 8, 9. Specifically, the iodide and bromide based CH 3 NH 3 PbX 3 have drawn extensive attention for their breakthrough performance in thin film mesoporous oxide solar cells where power conversion efficiencies of nearly 20% have already been reported 7, 9, 10, 11, 12, 13, 14, 15, 16. The same material also shows great potential in lasing and LEDs applications 17, 18, 19, 20…”