Research on the photoluminescence properties and stability of Cu²⁺‐doped perovskite <scp>CsPbCl₁</scp>_.<scp>₅Br₁</scp>_.5 quantum dots

Abstract Cu:CsPbCl x Br 3‐x quantum dots (QDs) with different Cu‐to‐Pb molar ratios were synthesized via a solvent‐based thermal synthesis method, and highly stable blue‐light PCL@Cu:CsPbCl x Br 3‐x composite fibers (CFs) were prepared by electrohydrodynamic (EHD) technology. The photoluminescence (PL) properties of these Cu 2+ ‐doped Cu:CsPbCl x Br 3‐x QDs and the stability of polymer encapsulation were investigated in this study. The results showed that with increasing Cu 2+ concentration, the CsPbCl 1.5 Br 1.5 QDs maintained their initial cubic crystal structure. The doping of Cu 2+ ions effectively eliminated the surface defects of CsPbCl 1.5 Br 1.5 QDs, facilitating excitonic recombination through radiative pathways. The PL quantum yield (PLQY) of Cu:CsPbCl 1.5 Br 1.5 QDs increased to 85%. In addition, The fiber encapsulation method effectively improved the stability of the Cu:CsPbCl 1.5 Br 1.5 QDs, After 3 days in water, the fluorescence intensity still remains at the initial 90%. Based on these results, it is believed that Cu:CsPbCl 1.5 Br 1.5 QDs have promising applications in optoelectronic devices in the future.