Solution‐Processed Perovskite Microdisk for Coherent Light Emission

Abstract

AbstractHigh‐quality semiconductor microdisks (MDs) are of crucial importance for realizing on‐chip coherent light sources. However, the fabrication of all‐inorganic semiconductor circular or circular‐like microdisks (CMDs) with suitable size for optoelectronic applications is still complex and expensive. Herein, a facile ligand‐free antisolvent‐assisted growth method is used to synthesize high‐quality Cs4PbBr6 MDs with tunable size and morphology, which is evolved from rhombohedral to octahedral, hexagonal‐like, and circular‐like MDs based on Cl‐containing antisolvents. Significantly, this is the first time that large semiconductor CMDs are synthesized from solution self‐assembled growth at room temperature. These Cs4PbBr6 MDs show high‐efficient and stable green emission (522 nm), which should be attributed to the first‐order excitonic emission from embedded CsPbBr3 nanocrystals (NCs). The distribution of CsPbBr3 NCs is verified by lattice fringe, crystal data refinement, and time‐resolved photoluminescence analysis. These CsPbBr3‐in‐Cs4PbBr6 CMDs are demonstrated to hold outstanding two‐photon pumped coherent light emission ability with a remarkably low threshold (400 µJ cm−2). These findings suggest CsPbBr3‐in‐Cs4PbBr6 MDs have excellent light emission capability and stability toward practical optoelectronic applications, and their tunable morphology and size indicate that solution method is feasible for the fabrication of semiconductor CMDs.