Up-Conversion Perovskite Nanolaser with Single Mode and Low Threshold

Perovskite nanocrystals open up a bright future for nanolasers, for their various instinct advantages (such as large absorption cross section and optical gain, high fluorescence quantum yields, etc.) can greatly benefit the design and fabrication of nanolasers with a low threshold, high emission efficiency, and good integration. Although numerous investigation efforts have been devoted to exploring the perovskite nanolaser of the single-photon-pumped type, the study of up-conversion lasing excited by two-photon-pumping is still established on the structures of micrometer scale with multiple mode, which is not in favor of improving the working stability and scale miniaturization of future nanolasers. To expand the application of the perovskite nanocrystal in nanolasers, we studied the perovskite (CsPbX3, X = Cl, Br) nanoplates fabricated by the supersaturated recrystallization approach and observed single mode up-conversion lasing from a single nanoplate with a low threshold of 4.84 μJ/cm2. In addition, theoretical calculations demonstrated that such single mode lasing could be attributed to the whispering gallery mode supported by the nanoplate cavity. Our findings not only prove the great potentials of perovskite nanoplate in building an up-conversion nanolaser but also further our understanding of lasing behaviors in nanoscale perovskite materials.