Research on the photoluminescence properties of Cu-doped perovskite CsPbCl quantum dots

CsPbX 3 (X = Cl, Br, and I) quantum dots (QDs) and Cu 2+ -doped CsPbCl 3 QDs with different Cu-to-Pb molar ratios were synthesized via a solvent-based thermal synthesis method. The photoluminescence (PL) properties of these Cu 2+ -doped CsPbCl 3 QDs were also investigated in this study. The results showed that with the increase in the Cl − concentration the surface defects of CsPb(Cl/Br) 3 QDs increased, which resulted in an increase in the non-radiative recombination of excitons and weakened the PL intensity. Moreover, Cu 2+ -doped CsPbCl 3 QDs maintained the cubic crystal structure of the initial phases. Owing to the doping of Cu 2+ ions, the surface defects of CsPbCl 3 QDs were effectively eliminated, which facilitated the excitonic recombination via a radiative pathway. The PL quantum yields (PLQYs) of Cu 2+ -doped CsPbCl 3 QDs were increased to 51%, showing great photostability. From the results, it is believed that Cu:CsPbCl 3 QDs can be widely used in optoelectronic devices. Schematic of the synthesis of Cu:CsPbCl 3 QDs and PL spectra.