Upconversion Luminescence in Yb/Ln (Ln = Er, Tm) Doped Oxyhalide Glasses Containing CsPbBr3 Perovskite Nanocrystals

Abstract

Yb/Ln (Ln=Er, Tm) doped TeO2-based glasses containing CsPbBr3 perovskite quantum dots were successfully prepared via in-situ glass crystallization. The nanocomposites yield typical green downshifting luminescence attributing to CsPbBr3 exciton recombination under UV excitation, and produce Er3+ green, Er3+ red and Tm3+ blue upconversion emissions under 980 nm laser excitation. Impressively, specific Ln3+ emissions will be quenched with the precipitation of CsPbBr3 in glass, enabling to finely tune upconversion emitting color. Spectroscopic characterizations evidence that the luminescence quenching is originated from non-radiative reabsorption effect induced by the precipitation of CsPbBr3 rather than energy transfers from Ln3+ to CsPbBr3. Finally, these nanocomposites are demonstrated to exhibit superior water resistance due to the effective protecting role of dense structural glass, particularly, about 95% downshifting luminescence of CsPbBr3 and upconversion luminescence of Er3+ related to pristine ones are retained after immersing the products in water up to 30 days.