High-Quality Whispering-Gallery-Mode Lasing from Cesium Lead Halide Perovskite Nanoplatelets

Semiconductor micro/nano-cavities with high quality factor (Q) and small modal volume provide critical platforms for exploring strong light-matter interactions and quantum optics, enabling further development of coherent and quantum photonic devices. Constrained by exciton binding energy and thermal fluctuation, only a handful of wide-band semiconductors such as ZnO and GaN have stable excitons at room temperature. Metal halide perovskite with cubic lattice and well-controlled exciton may provide solutions. In this work, high-quality single-crystalline cesium lead halide CsPbX3 (X = Cl, Br, I) whispering-gallery-mode (WGM) microcavities are synthesized by vapor-phase van der Waals epitaxy method. The as-grown perovskites show strong emission and stable exciton at room temperature over the whole visible spectra range. By varying the halide composition, multi-color (400-700 nm). WGM excitonic lasing is achieved at room temperature with low threshold (similar to 2.0 mu J cm(-2)) and high spectra coherence (similar to 0.14-0.15 nm). The results advocate the promise of inorganic perovskites towards development of opto-electronic devices and strong light-matter coupling in quantum optics.Singapore National Research Foundation (NRF) [NRF-NRFI2015-03]; Competitive Research Program [NRF-CRP-6-2010-2]; Singapore Ministry of Education through AcRF [MOE2011-T2-2-051, MOE2015-T2-1-047]; Nanyang Technological University [M4080514]; Ministry of Education AcRF [RG101/15, MOE2013-T2-1-081, MOE2014-T2-1-044]; NRF through Singapore-Berkeley Research Initiative for Sustainable Energy (SinBerRISE) CREATE Programme; Competitive Research Program grant [NRF-CRP14-2014-03]SCI(E)EIARTICLEtzechien@ntu.edu.sg; Qihua@ntu.edu.sg346238-62452