▎ 摘　　要

An annealing-free hole transport layer based on oxygen deficient molybdenum oxide (MoO3-x) nanosheets was developed for polymer solar cells. It showed performance comparable to that of PEDOT:PSS. For better hole extraction, graphene oxide (GO) was introduced to form a GO/MoO3-x bilayer as a hole transport layer to further improve the device performance.