Metal-doping for perovskite optoelectronic applications

The last decade has witnessed a surge of research interests in metal halide perovskites, driven by their captivating optoelectronic characteristics. Introducing exotic metal ions for A- or B-site doping has been acknowledged as a viable strategy to enhance the quality of perovskite films and modify their intrinsic properties for different optoelectronic applications. Despite the great success of metal-doping strategy for perovskites, a systematic overview regarding their doping mechanisms and the precise roles of metal dopants is lacking. In this review, we first present an introduction regarding the fundamental understanding of metal-doping behavior, followed by a systematic analysis on the recent advances of metals ions (alkali metals, post-transition metals, alkaline-earth metals, transition metals and lanthanide rare-earth metals)-doping in perovskites for photovoltaic applications and beyond. An in-depth understanding of metal-doping mechanisms in perovskites was concluded, covering the dopant distributions and their impacts on tuning the crystal structure as well as optoelectronic properties of perovskite films. Finally, the insightful perspectives of metal-doping strategy in perovskite are provided to illuminate the future advancements in metal-doped perovskite optoelectronics.