Influence of the Surface Modification on Carrier Kinetics and ASE of Evaporated Perovskite Film

All inorganic cesium lead halide perovskite has emerged as promising optical gain materials due to its excellent optical properties. Carrier recombination and amplified spontaneous emissions (ASE) threshold affect their performance on lasing applications. Herein, CsPbBr3 films were prepared using thermally evaporated method with uniform and high coverage surface. Ammonium salt (PABr) was used to further modify the film. The modified sample exhibited flattened surface morphology, enhanced light-emission, suppressed trap-assisted recombination and Auger recombination, thus improving the efficiency of radiation recombination. It was found that the PABr modified CsPbBr3 exhibit an ASE threshold of 25.45 uJ cm-2 which is lower than that of pure CsPbBr3 with 31.5 uJ cm-2. This work suggest that the thermally evaporated method interfacial modification could provide an effective strategy to ameliorate the room-temperature stimulated emission of CsPbBr3.