Rare earth doping in perovskite luminescent nanocrystals and photoelectric devices

Abstract Halide perovskites have shown great promise in optoelectronics and photovoltaics owing to their outstanding photoelectrical properties. However, their inherent shortcomings, such as lack of near‐infrared (NIR) photoluminescence (PL), instability and low efficiency, limit their practical applications. It is notable that doping and ion substitution represent effective strategies for tailoring the optoelectronic properties and stabilities of perovskite nanocrystals (NCs). Rare earth (RE) ions exhibit unique electronic and optical properties; the combination of lead halide perovskite and RE ions can combine the excellent optoelectronic properties of the host with the f‐f electronic transitions of the dopants and promote the further development of perovskite in the field of optoelectronics. For example, the efficient quantum cutting phenomenon in Yb3+‐doped CsPb(Cl/Br)3 NCs yields a photoluminescence quantum yield (PLQY) close to 200%, which have enabled promising proof‐of‐principle demonstration of solar photovoltaics. This review comprehensively summarizes the crystal structure, synthesis strategy, and applications of RE‐doped halide perovskites. We systematically discussed the challenges of RE ions in halide perovskite photovoltaic and light‐emitting devices, which provided a leading direction for the development of efficient and stable perovskite photovoltaic devices in the future.