Random lasing in solution-processed perovskite thin films

Summary form only given. The past few years have witnessed an unprecedented development in the field of perovskite metal halide solar cells. Thanks to the excellent optoelectronic properties of the semiconducting perovskite thin films, organometal trihalide perovskite based photovoltaic devices have achieved efficiencies as high as 22% [1]. While much of the research activities on perovskite have focused on improving the efficiency of solar cells, it has also been employed as a light emitting material. Recently, there have been encouraging results on using perovskite thin films in light-emitting diodes (LEDs), tunable amplified spontaneous emission and lasers [2].In summary, we have demonstrated single and multi-modal random lasing action in uniform perovskite films fabricated by a simple solution-based deposition method at room temperature. We also show methods to control the random lasing by varying the deposition parameters, i.e. control of film crystallisation, which has a significant impact on both optical gain and loss, thereby providing a clear guideline for the fabrication of the ultimate low-threshold perovskite laser.