Cerium-based halide perovskite derivatives: A promising alternative for lead-free narrowband UV photodetection

Metal halide perovskites are promising for optoelectronic applications but face challenges like lead toxicity, poor stability, and low photoluminescence quantum yield (PLQY). Cs₃CeBr₆, a non-toxic rare-earth material, is a potential lead-free alternative. As the synthesis of Cs₃CeBr₆ traditionally requires high temperatures, this study presents a low-temperature, eco-friendly, and cost-effective method for its formation. The material exhibits a narrow UV excitation range (280–370 nm) and emits violet light with an impressive PLQY of ∼89% and a photoluminescence (PL) decay time of 28.3 ns. Utilizing these properties, an efficient spectrum-selective visible-blind UV photodetector was developed, demonstrating exceptional responsivity (2.05 A/W) and high detectivity (10¹³ Jones) at low bias voltage (1 V). The device shows long-term stability and energy efficiency. This study explores carrier transport and defect dynamics in thin films to enhance UV responsiveness, marking a significant advancement in low-power-consumption device technology.