Influence of Ce3+ Doping on Photoluminescence Properties and Stability of Cs4SnBr6 Zero-Dimensional Perovskite

Zero-dimensional tin-based halide perovskites have garnered considerable interest owing to their remarkable optical properties, including broad-band emission, high photoluminescence (PL) efficiency, and low self-absorption. Nevertheless, enhancing the PL efficiency and stability of these materials remains a pressing challenge. In this study, the enhancement of PL and stability in Cs4SnBr6 zero-dimensional perovskite was investigated through Ce3+ doping. Our experimental results demonstrate that the incorporation of Ce3+ can significantly boost the light emission intensity from self-trapped excitons (STEs) in Cs4SnBr6, achieving over a 150% increase compared to the undoped sample, with a PL quantum yield of approximately 64.7%. Moreover, the thermal stability of the corresponding doped sample is markedly enhanced. Through comprehensive analyses, including X-ray diffraction, energy-dispersive spectroscopy, time-resolved PL, and temperature-dependent PL measurements, we elucidate that the enhanced light emission is attributed to the distortion of the [SnBr6]4− octahedral structure induced by Ce3+ doping, which strengthens electron–phonon coupling and elevates the binding energy of STEs.