Organic/inorganic perovskite materials display unique optoelectronic properties. Recently, the power conversion efficiency of perovskite solar cells (PSCs) reaches record high of 22.1%, and expected to reach more than 25% in the near future by further enlarging the perovskite crystal size and passivating the surface/grain boundary defects, via reducing non-radiative carrier recombination at the interface and/or in the bulk. In this special issue, 5 mini-reviews and 6 research papers are collected to cover the main research topics in PSCs.