All-inorganic CsPbBr3 perovskite quantum dots embedded in dual-mesoporous silica with moisture resistance for two-photon-pumped plasmonic nanoLasers.

Lead halide perovskite nanocrystals with efficient two-photon absorption and ease of achieving population inversion have been recognized as good candidates to achieve frequency up-conversion for biophotonics applications, but suffer from the limitation of the miniaturization of the device and its corresponding poor stability when exposed to atmospheric moisture. Here we demonstrate the miniaturization of plasmonic nanolasers via embedding perovskite quantum dots (QDs) in rationally designed dual-mesoporous silica with gold nanocore. The nanocomposite supports resonant surface plasmon-polaritons (SPPs), which overlap both spatially and spectrally with the CsPbBr3 QDs. The outcoupling between surface plasmon oscillations and photonics modes within a wavelength range completely overcomes the loss of localized surface plasmons, and finally contributes to a novel application of two-photon-pumped nanolasers. Large optical gain under two-photon excitation was observed as a result of resonant energy transfer from excited perovskite QDs to surface plasmon oscillations and stimulated emission of surface plasmons in a luminous mode. The outmost organic-inorganic hybrid shells of the dual-mesoporous silica nanocomposites act as a protective layer of the perovskite QDs against water and endow the nanocomposites with superhydrophobicity. This work provides an alternative inspiration for the design of new two-photon pumped nanolasers.