The preparation and up-conversion properties of full spectrum CsPbX3 (X = Cl, Br, I) quantum dot glasses

Abstract

All-inorganic perovskite (CsPbX₃) quantum dots (QDs) have achieved unprecedented success in various applications due to their outstanding performance. Nevertheless, the inherent instability of these QDs severely limits their practical applications. Here, ultra-stable full visible spectrum CsPbX₃ (X = Cl, Br, I) QD glasses are prepared successfully. For the first time, the full spectrum tunable up-conversion (UC) emission of CsPbX₃ QD glasses ranging from 420 nm to 711 nm under excitation with an 800 nm femtosecond (fs) laser was achieved. Importantly, the two-photon absorption properties, the exciton binding energy and the UC full width at half maximum (FWHM) of CsPbCl_1.5Br_1.5 (blue), CsPbBr₃ (green), and CsPbBr_1.5I_1.5 (red) QD glasses were studied in depth. Furthermore, CsPbCl_1.5Br_1.5 showed the highest exciton binding energy (∼87.5 meV), allowing the CsPbCl_1.5Br_1.5 QD glass to act as a good optical gain material that could more easily achieve amplified spontaneous emission (ASE).