Bi³⁺‐doped CsPbX₃ (X = Cl/Br, Br, Br/I, I) quantum dots in borogermanate glasses for short‐wave cut‐off filters

Abstract For short‐wave cut‐off filter application, the CsPbX 3 (X = Cl/Br, Br, Br/I, I) perovskite quantum dots (QDs) glasses have been modified by Bi 3+ doping based on borogermanate glass matrix. The structure, transmittance (T%), optical density (OD), photoluminescence (PL), PL excitation (PLE), and PL decay of the nanocrystals have been investigated for graded concentrations of Bi 3+ . The Bi 3+ is partially doped into the CsPbX 3 nanocrystals, and the Bi 3+ ‐doped nanocrystals are cubic structure. The Bi 3+ doping significantly suppresses the fluorescence intensity and shortens the PL lifetime for exciton emission of QDs, whereas key performance parameters of filters for the T% and OD are not significantly affected. The operation wavelength is tuned from blue to red light range by varying the halogen anion concentration and ratio. The optimized QDs glass exhibits excellent short‐wave cut‐off filtering properties, while effectively circumventing exciton emission interference. The decrease in PL intensity and average lifetime for the CsPbX 3 QDs is attributed to the deep energy level traps by Bi 3+ doping. This study provides a Bi 3+ doping quenching strategy for the development of high‐performance optical filter materials.