Research on the photoluminescence properties of Cu2+-doped perovskite CsPbCl3 quantum dots

CsPbX3 (X = Cl, Br, and I) quantum dots (QDs) and Cu2+-doped CsPbCl3 QDs with different Cu-to-Pb molar ratios were synthesized via a solvent-based thermal synthesis method. The photoluminescence (PL) properties of these Cu2+-doped CsPbCl3 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, Cu2+-doped CsPbCl3 QDs maintained the cubic crystal structure of the initial phases. Owing to the doping of Cu2+ ions, the surface defects of CsPbCl3 QDs were effectively eliminated, which facilitated the excitonic recombination via a radiative pathway. The PL quantum yields (PLQYs) of Cu2+-doped CsPbCl3 QDs were increased to 51%, showing great photostability. From the results, it is believed that Cu:CsPbCl3 QDs can be widely used in optoelectronic devices.