Doped Charge-Transporting Layers in Planar Perovskite Solar Cells

Organometal halide perovskite solar cells (PSCs) are brought to the forefront of research focus in photovoltaics field with a rapid efficiency rising over 22% in the past few years. Interface engineering with suitable hole-transporting layer (HTL) and/or electron-transporting layer (ETL) plays very important roles in controlling the charge carrier behavior in planar PSCs. Particularly, the utilization of doped charge-transporting layers is regarded as an efficient route to further improve the device performance of the planar PSCs. In this review, first the fundamental roles of doped charge-transporting layers are briefly introduced. Then, the review mainly summarizes the recent progress in the development of doped HTLs and ETLs. Finally, a prospective of promising applications of doped charge-transporting layers in planar PSCs is proposed.