Metal-ion doping in Pb-free Cu-based perovskites: luminescence, and application of light-emitting diodes and scintillators

Abstract Metal halide perovskite materials have attracted extensive interest in optoelectronic devices owing to their superior optoelectronic properties, yet the lead toxicity and structural instability severely impede practical applications. Lead-free Cu-based perovskites, as potential alternatives, exhibit environmental benignity and favorable optoelectronic tunability, emerging as a research hotspot in materials science in recent years. This paper systematically reviewed the metal ion doping in Cs ₃ Cu ₂ I ₅ nanocrystals (NCs), with a focus on the regulatory mechanisms of crystal structure, luminescence properties, and optoelectronic applications. We summarized the modulation effects of metal-ion doping on lattice distortion, electronic structure, and defect density through A-site/B-site substitution. Meanwhile, we presented the luminescence optimization of photoluminescence and radioluminescence via defect passivation and energy level modulation. In addition, we indicated the applications of such NCs in light-emitting diodes and scintillators for radiation detection. Finally, we designated the current challenges and prospected directions for further improving material and device performance for further development of lead-free perovskites.