Excitonic optical properties and lasing mode shifts in square CsPbBr3 nanoplate cavities

Abstract

Cesium lead bromide (CsPbBr3) perovskite micro/nanostructures have potential applications in miniaturized integrated light sources due to their confined modal volume and high luminous efficiency. In this work, we synthesized CsPbBr3 nanoplates with regular square shapes and smooth surface by the chemical vapor deposition method. The temperature-dependent and excitation power-dependent photoluminescence spectra reveal the excitonic photoluminescence properties. The whispering gallery mode (WGM)-like lasing in CsPbBr3 nanoplates was observed at room temperature. We systematically investigated the pump fluence-dependent multi-mode and single-mode lasing actions in square microcavities. The blueshift of individual lasing modes can be attributed to the variation of refractive index resulting from the formation of the electron-hole plasma (EHP) state under highly injected carrier density. The results reveal the dependence of emission properties on excitation intensity, providing further understanding of the carrier-induced mode shift mechanism in the WGM-like lead halide perovskite microcavities.