Research on photodetectors based on zinc-doped tin-lead perovskite quantum dots

Abstract The problems of Sn 2+ being easily oxidized and the limited water-oxygen stability of Sn 2+ -doped CsPbBr 2 I quantum dots (QDs) have hindered the further advancement of optoelectronic devices based on these materials, representing a key challenge in the field. In this study, we employed a double-doping strategy to prepare Sn-Zn:CsPbBr 2 I QDs. The incorporation of Zn 2+ effectively contracts the crystal lattice and blocks oxygen diffusion pathways, thereby suppressing the oxidation of Sn 2+ , which was confirmed by X-ray diffraction (XRD) testing. Furthermore, the introduction of Zn 2+ enhances the optical performance of the QDs. At an optimal Pb/Sn/Zn molar ratio of 0.85/0.10/0.05, the photoluminescence (PL) intensity increased by 78% compared to that of CsPbBr 2 I QDs. Additionally, the photodetector fabricated with Sn-Zn:CsPbBr 2 I QDs exhibited a responsivity of 0.44 A/W and a specific detectivity of 1.42×10 13 Jones, outperforming the CsPbBr 2 I QDs-based device (0.38 A/W and 6.07×10 12 Jones). This work offers a new approach to enhancing the stability of Sn:CsPbBr 2 I QDs and supports the development of low-toxicity, and high-performance optoelectronic devices.