Yang's group has made notable contribution to the perovskite solar cell society and greatly enhanced the efficiency and stability of the metal halide perovskite solar cells, which is regarded as the new generation of the photovoltaic technique because of its low cost, high absorption coefficient, and ease of fabrication. In this talk, he will briefly introduce the unique merits of the perovskite material and address the fundamental factors of its stability issue. Impactful strategies developed by Yang’s group including selected additives for defect passivation and controlled grain growth, grain boundary minimization, and surface post-treatment reforming the interfaces of the perovskite and transport layers will be discussed. With largely improved operational stability and comparable power conversion efficiency compared to the silicon solar cell, we are expecting a promising upcoming era of perovskite solar cell commercialization. Finally, a few words about the status of the Y6 molecules will also be mentioned.