Spectral Tuning, Stabilities under External Exposures, and Spontaneous Enhancement of Emission Intensity in Grown-into-Glass All-Inorganic Metal Halide Perovskite Nanocrystals

Abstract

Herein, the grown-into-glass (GIG) CsPbBr3:Ln3+ (Ln = La, Lu) nanocrystals (NCs) are designed and fabricated using an in situ nanocrystallization method. It is shown that a substitution of Pb2+ sites with Ln3+ ions leads to a blueshift of emission position induced by an increase of the bandgap of CsPbBr3. Additionally, the GIG-samples are found to feature excellent photoluminescent (PL) properties after being immersed respectively in water for 300 days at room temperature, boiling water for 12 h, and corrosive environments for 24 h, as well as recoverable PL intensity either after several cycles of heat-cooling experiments or after being continuously exposed to a 405 nm laser irradiation. Besides, a spontaneous enhancement of 20-25% of emission intensity during the 1-2.5 hours' stage of a 405 nm laser irradiation, attributed to the radiative recombination of charge carriers that can be de-trapped from trapping levels upon the laser light irradiation and that then spontaneously reinforces the emission intensity, is observed in the GIG-CsPbBr3:Ln3+ NCs. Finally, a white light-emitting prototype, with a CIE chromaticity coordinate at (0.4110, 0.3706), a color rendering index of 89 and a correlated color temperature of 3363 K is realized by combining the GIG-CsPbBr3 NCs, YAG:Ce and CaWO4:Eu phosphors.