Using Interfacial Contact Engineering to Solve Nickel Oxide/Perovskite Interface Contact Issues in Inverted Perovskite Solar Cells

Perovskite is a promising photovoltaic material in the sustainable energy field. In inverted perovskite solar cells (PSCs), the bottom p-type hole transport materials play a crucial role in the device power conversion efficiency (PCE) and ambient stability. Nickel oxide (NiO X ) is the most promising inorganic hole transport material for inverted PSCs. However, the inferior interfacial contact of NiO X /perovskite has limited the improvement of inverted PSC performance. Strategies for handling this interfacial contact issue are scarce, and most of them require expensive equipment and complex preparation procedures. Herein, a new facial route was introduced to enhance the NiO X /perovskite interfacial contact using a porous morphology produced with a polyvinyl butyral (PVB) additive. Moreover, a bilayer-NiO X hole transport layer structure was successfully designed and used for fabricating a high-performance inverted PSC. The device exhibited a PCE of 17.57% and sufficient stability in ambient air. Various characterizations were performed to investigate the effect of the bilayer-NiO X film on device performance. The PSC exhibited superior performance, which was because of the enhanced perovskite film quality and the excellent bilayer-NiO X charge transfer ability and trap density reduction.