Here I will introduce our main achievements in the fabrication of efficient and stable PSCs with working area over one square centimeter. The first recorded efficiency of perovskite solar cells was obtained by using heavily doped inorganic charge extraction layers with high conductivity. New graded heterojunction (GHJ) structure was designed to improve the electron collection and in inverted structure with Formamidinium based perovskites. Combined with additive engineering, a certified efficiency of 19.2% was achieved.