Random lasing in uniform perovskite thin films

. By carefully controlling the solution processing conditions, we can determine whether random lasing occurs or not, using identical precursors. A rather special feature is that some of the films exhibit single and dual mode lasing action, which is rarely observed in random lasers. Our work fully exploits the simplicity of the solution-based process and thereby adds an important capability into the emerging field of perovskite-based light emitters.