Enhanced Photoluminescence and Stability of F − /Sm 3+ Codoped CsPbBr 3 Quantum Dot Glass Composites

All‐inorganic perovskite quantum dots (QDs) (CsPbX 3 , X = Cl, Br, I) have shown great promise in optoelectronic applications but are severely hindered by their poor environmental stability and photoluminescence (PL) quenching. In this work, we report a novel approach for enhancing both stability and optical performance by insitu growth of CsPbBr 3 QDs within a borosilicate glass matrix, assisted by SrF 2 and Sm 2 O 3 codoping. The introduction of F − ions from SrF 2 modifies the glass network structure, promoting uniform nucleation and growth of QDs. Simultaneously, Sm 3+ doping, through partial incorporation into the CsPbBr 3 QD lattice, passivates surface defects and induces lattice contraction, which enhances quantum confinement effects. At the optimal Sm 3+ concentration of 1 mol%, the PL intensity increases by 332.8%, the photoluminescence quantum yield rises from 22.01% to 37.5%, and the fluorescence lifetime extends from 95.05 to 127.69 ns. The glass encapsulation provides long‐term air and water stability, outperforming conventional ligand‐capped QDs. Moreover, the developed materials were successfully applied in high‐brightness green and white light‐emitting diodes, achieving wide color gamut coverage (up to 129.4% NTSC), and demonstrated strong potential in forensic fingerprint visualization. These results provide a new pathway for developing stable, multifunctional perovskite‐based optoelectronic materials.