Efficient Low‐Temperature Solution‐Processed Lead‐Free Perovskite Infrared Light‐Emitting Diodes

Lead-free perovskite infrared light-emitting diodes are achieved by using a halide perovskite CsSnI3 as an emissive layer. The film shows compact micrometer-sized grains with only a few pinholes and cracks at the grain boundaries. The device exhibits maximum radiance of 40 W sr-1 m-2 at a current density of 364.3 mA cm-2 and maximum external quantum efficiency of 3.8% at 4.5 V.