Metal halide perovskite solar cell (PSC) has successfully distinguished itself in optoelectronic field by virtue of the sharp rise in power conversion efficiency over the past decade. The remarkable efficiency breakthrough at such a fast speed can be mainly attributed to the comprehensive study on film deposition techniques, especially the effective management of surface and interfacial defects in recent works. Herein, we summarized the current trends in performance enhancement for PSCs, with a focus on the generally applicable strategies in high-performance works, involving deposition methods, compositional engineering, additive engineering, crystallization manipulation, charge transport material selection, interfacial passivation, optical coupling effect and constructing tandem solar cells. Promising directions and perspectives are also provided.

Hole transport material free carbon-based all-inorganic CsPbBr₃ perovskite solar cells (PSCs) are promising for commercialization due to its low-cost, high open-circuit voltage (V_oc) and superior stability. Due to the different solubility of PbBr₂ and CsBr in conventional solvents, CsPbBr₃ films are mainly obtained by multi-step spin-coating through the phase evolution from PbBr₂ to CsPb₂Br₅ and then to CsPbBr₃. The scalable fabrication of high-quality CsPbBr₃ films has been rarely studied. Herein, an inkjet-printing method is developed to prepare high-quality CsPbBr₃ films. The formation of long-range crystalline CsPb₂Br₅ phase can effectively improve phase purity and promote regular crystal stacking of CsPbBr₃. Consequently, the inkjet-printed CsPbBr₃ C-PSCs realized PCEs up to 9.09%, 8.59% and 7.81% with active areas of 0.09, 0.25, and 1 cm², respectively, demonstrating the upscaling potential of our fabrication method and devices. This high performance is mainly ascribed to the high purity, strong crystal orientation, reduced surface roughness and lower trap states density of the as-printed CsPbBr₃ films. This work provides insights into the relationship between the phase evolution mechanisms and crystal growth dynamics of cesium lead bromide halide films.