Room-Temperature Red–Green–Blue Whispering-Gallery Mode Lasing and White-Light Emission from Cesium Lead Halide Perovskite (CsPbX₃, X = Cl, Br, I) Microstructures

Wavelength-tunable nano/microlasers are essential components for various highly integrated and multifunctional photonic devices. Based on the different band gap/composition of inorganic cesium lead halide perovskite materials, broad band light absorption and emission devices can be achieved. Herein, a vapor–liquid–solid route for growing cesium lead halide perovskite (CsPbX₃, X = Cl, Br, I) microcrystal structures is demonstrated. These square-shaped microstructures exhibit strong blue, green, and red photoluminescence, indicating that their band gaps can be engineered to cover the entire visible range. Optically pumped red–green–blue whispering-gallery mode lasers based on the controlled composition of these microcrystals are successfully realized at room temperature. Moreover, rationally designed white-light-emitting chips with high brightness are fabricated utilizing these metal halide perovskite microstructures grown on sapphire. All these results evidently suggest a feasible route to the design of red–green–blue lasers and white-light emitters for potential applications in full-color displays as well as photonic devices.