High-Performance Inverted Perovskite Solar Cells with Sol-Gel-Processed Sliver-Doped NiOX Hole Transporting Layer

Nickel oxide (NiOX) has been established as a highly efficient and stable hole-transporting layer (HTL) in perovskite solar cells (PSCs). However, existing deposition methods for NiOX have been restricted by high-vacuum processes and fail to address the energy level mismatch at the NiOX/perovskite interface, which has impeded the development of PSCs. Accordingly, we explored the application of NiOX as a hybrid HTL through a sol-gel process, where a NiOX film was pre-doped with Ag ions, forming a p/p(+) homojunction in the NiOX-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.

Automated summary

Nickel oxide (NiOX) has been proven to be an efficient hole-transporting layer (HTL) in perovskite solar cells (PSCs). However, current deposition methods for NiOX are limited and fail to address the energy level mismatch at the NiOX/perovskite interface, hindering the development of PSCs. In this study, a sol-gel process was utilized to create a hybrid HTL by pre-doping a NiOX film with Ag ions, forming a p/p(+) homojunction in the NiOX-based inverted PSCs. This innovative approach enhanced charge separation, energy level alignment, and charge transfer efficiency at the perovskite/HTL interface, resulting in a high-power conversion efficiency (PCE) of 19.25% and improved environmental stability.