Photoluminescence Characteristics of Sn2+ and Ce3+-Doped Cs2SnCl6 Double-Perovskite Crystals.

In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs₂SnCl₆ double perovskite crystals were prepared by aqueous phase precipitation method using SnCl₂ as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce³⁺-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [ S n S n 4 + 2 + +V_Cl] defect complex in the crystal is formed by Sn²⁺ substituting Sn⁴⁺. The number of defects formed by Sn²⁺ in the crystal decreases with Ce³⁺ content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [ S n S n 4 + 2 + +V_Cl] decreased. When Ce³⁺ is incorporated into the crystals, the defects of [ C e 3 + S n 4 + +V_Cl] and [ S n S n 4 + 2 + +V_Cl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs₂SnCl₆ double perovskite crystals. [ABSTRACT FROM AUTHOR]