Whispering Gallery Mode Lasing from Perovskite Polygonal Microcavities via Femtosecond Laser Direct Writing

Organic-inorganic halide perovskites have excellent intrinsic properties, such as long carrier lifetime, high photoluminescence quantum yield, and high gain, in whispering gallery mode (WGM) cavities by facile vapor self-assembly or solution process, which make them competitive for high-performance microlasers. However, the performance of perovskite-based microlasers is severely limited by the fabrication of microcavities, which results in poor reproducibility and uncontrolled morphology. Herein, we explore a reproducible method which combined thermal co-evaporation with femtosecond (fs) laser direct writing for formamidinium lead iodide (FAPbI(3)) perovskite polygon-shaped WGM microcavities. The microlasers pumped with the fs laser had a low threshold of 4.0-12.3 mu J/cm(2) and narrow full width at half-maximum of 0.62-1.05 nm. Moreover, size- and shape-dependent WGM lasing performances are also investigated systematically. The results prove that FAPbI(3) polygonal microcavities can serve as promising WGM lasers and have great potential for practical optoelectronic applications.

Automated summary

Organic-inorganic halide perovskites exhibit excellent properties in WGM cavities, but the performance of perovskite-based microlasers is limited by the fabrication of microcavities. Researchers have developed a reproducible method combining thermal co-evaporation and femtosecond laser direct writing to create FAPbI(3) polygon-shaped WGM microcavities, and systematically investigated the size- and shape-dependent WGM lasing performances. The results show that FAPbI(3) polygonal microcavities have great potential as promising WGM lasers for practical optoelectronic applications.