Stable and enhanced frequency up-converted lasing from CsPbBr quantum dots embedded in silica sphere.

Perovskites have emerged as a class of cutting-edge light-emitting materials; however, their poor stability, due to the high sensitivity to moisture in the ambient environment, severely hinders their further application. Here, to obtain stable perovskite-based laser with excellent optical performance, all-inorganic perovskite CsPbBr quantum dots (QDs) evenly distributed into sub-micro silica sphere (CsPbBr-SiO) have been used as laser gain medium. The single silica sphere embedded by plentiful CsPbBr QDs demonstrates frequency up-converted lasing with compounded mode of random and whispering-gallery-mode (WGM) at room temperature. Furthermore, by incorporating the CsPbBr-SiO spheres into a microtubule, the frequency up-converted WGM lasing has been successfully achieved under two-photon excitation. Notably, the CsPbBr-SiO microtubule resonator exhibits a low lasing threshold of 430 μJ/cm, mostly due to the enhanced gain for CsPbBr QDs inside the silica sphere. Moreover, stable WGM lasing is observed under continuous optical pump for 140 min, benefited from the protection of silica shells, which isolate the QDs from the environmental conditions. The enhanced lasing performance provides an effective way for further exploration and application of perovskite-based micro/nano photonic devices.