Rare earth Nd3+-doped organic-inorganic hybrid perovskite quantum dots for white LED

Lead halide perovskite quantum dots (QDs) have garnered significant attention due to their tunable band gaps, unique quantum confinement effects, and high photoluminescence quantum yields (PLQYs). Among them, Organic-inorganic QDs make them promising candidates for optoelectronic devices such as quantum dot light-emitting diodes (QLEDs), solar cells, lasers, and photodetectors. However, the toxicity of lead (Pb) has raised environmental and health concerns, hindering their industrial application. To alleviate concerns about heavy metals Pb, extensive research has been conducted on B-site doping and the development of lead-free perovskites. Herein, we firstly developed B-site doping strategy on organic-inorganic hybrid perovskite QDs via rare-earth elements. Neodymium (III) (Nd³⁺) doped FAPbBr₃ QDs were prepared through the ligand-assisted reprecipitation method at room temperature. The B-site doping strategy could alleviate the heavy metal problem of Pb and modulate the band gap of FAPbBr₃ QDs facilely. The results demonstrated that increasing the concentration of Nd³⁺ can change the emission of FAPbBr₃ QDs from pure green to deep blue. Specifically, we achieved highly pure blue emission (∼438 nm) with a full width at half maximum (FWHM) of 13 nm for Nd³⁺-doped FAPbBr₃ QDs. Time-resolved photoluminescence (TRPL) spectroscopy revealed a decrease in the lifetime of FAPbBr₃ QDs from 22.86 to 15.46 ns as the doping concentration increased. Additionally, we fabricated a white LED (WLED) utilizing blue-emitting Nd³⁺-doped FAPbBr₃, green-emitting FAPbBr₃ QDs, and red QDs, achieving a white emission color coordinate of (0.33, 0.36). This study pioneers the application of B-site rare-earth doping in organic-inorganic hybrid perovskite QDs, demonstrating that B-site composition engineering is a reliable strategy to further exploit the perovskite family for wider optoelectronic applications.