High-Performance Inverted Perovskite Solar Cells with Sol-Gel-Processed Sliver-Doped NiO_(x)Hole Transporting Layer

Nickel oxide(NiO_(x))has been established as a highly efficient and stable holetransporting layer(HTL)in perovskite solar cells(PSCs).However,existing deposition methods for NiO_(x)have been restricted by high-vacuum processes and fail to address the energy level mismatch at the NiO_(x)/perovskite interface,which has impeded the development of PSCs.Accordingly,we explored the application of NiO_(x)as a hybrid HTL through a sol-gel process,where a NiO_(x)film was pre-doped with Ag ions,forming a p/p^(+)homojunction in the NiO_(x)-based inverted PSCs.This innovative approach offers two synergistic advantages,including the enlargement of the built-in electric field for facilitating charge separation,optimizing energy level alignment,and charge transfer efficiency at the interface between the perovskite and HTL.Incorporating this hybrid HTL featuring the p/p^(+)homojunction in the inverted PSCs resulted in a high-power conversion efficiency(PCE)of up to 19.25%,significantly narrowing the efficiency gap compared to traditional n-i-p devices.Furthermore,this innovative strategy for the HTL enhanced the environmental stability to 30 days,maintaining 90%of the initial efficiency.