GeS2-Ga2S3 based glass ceramics containing doped with Er3+ CsPbBr3, CsPbI3 perovskite crystals: Effect of Er³⁺ Doping on Their Photoluminescent Properties

Glass-ceramics containing perovskite crystals CsPbX₃ (X = Br, I) doped with Er³⁺ were synthesized for the first time, using compositions of 80 mol.% GeS₂ − (5-y) mol.% Ga₂S₃ − 15 mol.% CsPbX₃ (y = 0–3 mol.% Er₂S₃). These materials exhibit photoluminescence (PL) with maxima at 530 nm (X = Br) and 688 nm (X = I), supported by perovskite crystals. In CsPbBr₃ glass-ceramics, PL intensity decreases with Er³⁺ doping due to a competing emission channel (660 nm) from Er³⁺ ions. Under 532 nm excitation, additional PL bands appear in the IR range at 805, 985, and 1540 nm. In the case of CsPbI₃ glass-ceramics, excitation with 980 nm light produces Antistokes (650 nm) and Stokes (1540 nm) emissions. Computational density functional theory (DFT) simulations provided insights into the structural and electronic properties of pristine and Er-doped CsPbX₃ crystals. The glass-ceramics remained stable, maintaining their PL properties for over a month.