Femtosecond laser direct writing of perovskite patterns with whispering gallery mode lasing

Hybrid perovskites have recently attracted attention in both materials science and opto-electronics research, because of their excellent opto-electronic properties and facile fabrication. Perovskitebased photovoltaic devices, photodetectors, and light-emitting diodes have exhibited unprecedented success. Moreover, optically pumped perovskite lasers have been reported with various crystal shapes. However, most of these lasers are fabricated from solutiongrown micro/nano crystals, and thus lack reproducibility. Here, we present controllable fabrication of formamidinium lead iodide(FAPbI3) perovskite microdisks by thermal co-evaporation, coupled with femtosecond laser direct writing. After careful investigation of dimensional effects, including the impact of diameter and thickness, we achieved an ultra-low threshold of B3 lJ cm2. Further￾ore, we investigated the relationship of lasing performance with carrier dynamics by transient absorption. We found that a longer carrier lifetime can reduce the pump threshold. These microdisk lasers based on femtosecond laser fabrication of evaporated per￾vskite thin films show exceptional reproducibility, rendering them extremely suitable for mass production; hence, they offer a promis￾ng method for low-cost, on-chip coherent light sources.

Journal of Materials Chemistry C