Abstract
Nickel oxide (NiOx) has proved as an efficient hole transport layer (HTL) for perovskite solar cells (PSCs) with inverted structure. However, NiOx is rarely adopted as HTL for standard structure organic photovoltaics (OPVs) with PEDOT:PSS still widely used despite their drawbacks that could affect the device's operational stability. Passivation of NiOx/perovskite interface with self-assembled monolayer or organometallic dye could increase the performance of single junction inverted PSCs by suppressing defect densities at the interface of NiOx. However, their application in OPVs has not been explored. This work investigates the effect of NiOx passivation with various organometallic dye molecules (N719, C106, N3, N749, Z907) for OPV application. Our results show that only NiOx-based devices modified with N3 exhibit an efficiency increase compared to those with pristine NiOx HTL. This work provides insights into the role of the energy alignment between the NiOx interface with the OPV's active layer.