Recently, perovskite quantum dots (QDs) have presented versatile potential applications in efficient photovoltaic cells and light-emitting devices such as bright light-emitting diode (LED) and lasing components. However, their poor stability, due to the high sensitivity to moisture in the ambient environment, severely hinders their further application.
A collaborative research team from Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences (CAS) and Chongqing University has succeeded in obtaining stable perovskite-based laser with enhanced emission. Their work was published on Optics Express.
At the beginning of the experiment, all-inorganic CsPbBr₃ perovskite QDs evenly distributed into sub-micro silica sphere (CsPbBr₃-Sio₂) were used as laser gain medium with facile hot-injection method. The single CsPbBr₃-Sio₂ sphere was demonstrated low-threshold frequency up-converted lasing with compounded mode of random and whispering-gallery-mode (WGM) at room temperature.
Furthermore, to purify the lasing mode, by incorporating the CsPbBr₃-Sio₂ spheres into a microtubule, the frequency up-converted pure WGM lasing were successfully achieved. Notably, the CsPbBr₃-Sio₂ microtubule resonator exhibited a lower lasing threshold of 430 μJ/cm² than reported in pure CsPbBr₃ QDs cases, mostly due to the enhanced gain for CsPbBr₃ QDs inside the silica sphere.
Moreover, stable WGM lasing was observed under continuous optical pump for 140 min, benefiting from the protection of silica shells, which isolate the QDs from the oxygen and moisture in the environmental conditions and lower the possibility of the aggregation induced quenching effect between QDs.
This research may provide an effective way for further exploration and application of perovskite-based micro/nano photonic devices.
This work was supported by the Strategic Priority Research Program of CAS and the National Natural Science Foundation of China.

 
Fig. 1 (a) Schematic diagram for measuring CsPbBr₃-Sio₂ QDs lasing.
(b) Emission spectra with increasing pump intensity under two-photon excitation.
(c) Log–log plot of the output intensity as a function of pump intensity.(image by SIOM)

Article website:
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-7-9459&origin=search
Contact:
Mr. Cao Yong
General Administrative Office
Shanghai Institute of Optics and Fine Mechanics, CAS
Email: caoyong@siom.ac.cn