Abstract
The power conversion efficiency of perovskite solar cells (PSCs) has been certified as a-22.1%, approaching the best single crystalline silicon solar cells. The improvement in the performance of PSCs could be achieved through the testing of novel materials in the device. This review briefly discusses the systematic introduction about several inorganic and organic electron-transporting materials (ETMs) and hole-transporting materials (HTMs) for efficient PSCs. The transport mechanism of electrons and holes in different ETMs/HTMs is also discussed on the basis of energy band diagrams with respect to the perovskite absorber. Moreover, the introduction of appropriate interfacial materials, hybrid ETMs, and doping is discussed to optimize the interfacial electronic properties between the perovskite layer and the charge-collecting electrode.