Space-resolved light emitting and lasing behaviors of crystalline perovskites upon femtosecond laser ablation

Femtosecond laser processing of lead halide perovskites has recently sparked wide popularity for creating various micro/nanostructures and instigating interesting properties. However, it is still lacking detailed insights into correlating the laser induced morphology and defect chemistry of perovskite materials to their light emitting properties. Here, the space-resolved photoluminescence and lasing behaviors are investigated for both the single crystal (SC) and polycrystalline (PC) perovskites upon femtosecond laser ablation. In the case of SC sample, three different regions based on the laser ablation, recast deposition, and modification respectively exhibits distinguished carrier recombination mechanisms due to their variable defect chemistries and morphologies identified, which helps to realize the amplified spontaneous emission with the recrystallized micro/nanostructures. On the other hand, the laser modified region on the PC sample reveals the significant enhancement of random lasing performance (the lasing threshold was reduced by ∼7 times and the slope efficiency increased by ∼1.5 times), which is attributed to the femtosecond laser induced non-radiative defect passivation and the average crystalline grain size reduction by more than 1.5 times. This study unveils the physical and chemical modification effects of the femtosecond laser irradiation on perovskite materials, and thus is an optimal strategy to fabricate desired perovskite light-emitting microstructures by ultrafast laser processing.