Fabry–Perot Mode-Limited High-Purcell-Enhanced Spontaneous Emission from <i>In Situ</i> Laser-Induced CsPbBr<sub>3</sub> Quantum Dots in CsPb<sub>2</sub>Br<sub>5</sub> Microcavities
Tianyuan Liang, Wenjie Liu, Xiaoyu Liu, Yuanyuan Li, Jiyang Fan
Abstract
The patterned metal halide perovskites exhibit novel photophysical properties and high performance in photonic applications. Here, we show that a UV continuous wave laser can induce in situ crystallization of individual and patterned CsPbBr3 quantum dots (QDs) inside the CsPb2Br5 microplatelets. The microplatelet acts as a natural Fabry–Perot cavity and causes the high-Purcell-effect-enhanced (by 287 times) cavity mode spontaneous emission of the embedded CsPbBr3 QDs. The luminescence exhibits a superlinear emission intensity–excitation intensity relation I(p) ∝ p2.83, and the exponent is much bigger than that of the free-space exciton spontaneous emission, suggesting arising of stimulated emission at higher photon concentrations. These laser-driven crystallized and patterned cavity mode luminescent perovskite QDs in a waterproof wider-bandgap perovskite microcavity act as an ideal platform for studying the cavity quantum electrodynamics phenomena and for applications in information storage and encryption, anticounterfeiting, and low-threshold lasers.