Stable continuous-wave lasing from discrete cesium lead bromide quantum dots embedded in a microcavityElectronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d3nh00139c

All-inorganic cesium lead bromide (CsPbBr3) quantum dots (QDs) with high photoluminescence (PL) quantum efficiency have been reported as ideal gain materials for high-performance lasers. Nevertheless, isolated CsPbBr3QDs have not achieved lasing emission (LE) due to finite absorption cross-section. Here, we demonstrate continuous-wave lasing of isolated CsPbBr3QDs embedded in a microcavity. Distributed Bragg reflectors (DBRs), together with isolated CsPbBr3QDs in a polymer matrix, are introduced to construct a vertical-cavity surface-emitting laser (VCSEL), which exhibits stable single-mode lasing emissions with an ultra-low threshold of 8.8 W cm−2and a high Qfactor of 1787. Such perovskite-based microcavity structures sustain highly stable excitons at room temperature and can provide an excellent experimental platform to further study the single-particle nano-lasers and quantum physics frontiers such as exciton–polariton condensation, single-photon emission, and optical quantum communication.