Ultrastability and color-tunability of CsPbI3 nanocrystals glass via doping CoBr2 and application in WLED

Abstract

Extensive research has been conducted on all-inorganic CsPbI3 nanocrystals (NCs) due to their exceptional optical properties. In this study, we successfully prepared CoBr2-doped CsPbI3 NCs in Lithium-borosilicate using the conventional melting quenching approach. We investigated the optical characteristics of CsPbI3 NCs glass doped with varying amounts of CoBr2. Remarkably, the samples exhibited outstanding water and thermal stability and tunable emission ranging from 702 to 652 nm. Interestingly, the CsPbI3 NCs glasses doped with CoBr2 demonstrated significantly enhanced photoluminescence quantum yields (PLQYs), which increased from 8 % to 32 %. Furthermore, by mixing a red CsPbI3 NCs glass doped with 0.5 mol CoBr2 and a green CsPbBr3 under a blue LED chip, we effectively generated a WLED which achieved (0.3341, 0.3360) of chromaticity coordinate (CIE), 5775.35 K of a correlated color temperature (CCT) that close to positive white light (0.330, 0.330) and the color rendering index (CRI) 79.4. This study provides a new technique in the field of metal ion-doped perovskite NCs, providing a valuable reference for future research and demonstrating possible applications in LEDs.