The metal doping strategy in all inorganic lead halide perovskites: synthesis, physicochemical properties, and optoelectronic applications.

All inorganic perovskites CsPbX (X = Cl, Br, I), rising stars of optical materials, have shown promising application prospects in optoelectronic and photovoltaic fields. However, some open issues still exist in these perovskites, like poor long-term stability, inevitable intrinsic defects and much nonradiative recombination, which greatly weakens their optical capability and seriously hinders their further development. The metal doping strategy, through the partial substitution of foreign ions for native ions, has gradually become an effective method for significantly enhancing the comprehensive properties of CsPbX. Whereas some previous studies have reported the impressive properties of metal-doped CsPbX, there is still a lack of a comprehensive review on the influences of metal doping on CsPbX. In this review, we aim to provide a systematic review of the latest achievements in metal-doped CsPbX, which focuses on their synthetic methods and the positive effects of metal doping on structure, optical properties, morphology control, carrier behavior and related optoelectronic and photovoltaic devices. Finally, we put forward a few opportunities and challenges about the further investigation of metal-doped perovskites, which may help researchers explore new research directions.