Sputtered NiOx as a Hole Transport Layer in n-i-p Perovskite Solar Cells Manufactured on Steel Substrate

Abstract

NiO x is one of the potential alternates for organic hole transport (HTL) layer in perovskite solar cells (PSCs) due to its low-cost and chemical stability. Inherent insulating properties of NiO x , and requirement of post-processing steps in its solution processing are the limiting factors which restricts its routine use for further development and applications. This work reports sputtered NiO x as HTL in n-i-p configured PSC having stainless-steel as a substrate. The best device showed a power conversion efficiency of 5.37%. It exhibited a short-circuit current density (J sc ) of −9.58 mA/cm2, open circuit voltage (V oc ) of 0.97V and a fill-factor (FF) of 58%. Due to the opaque nature of steel substrate, a semi-transparent ≈10 nm thin Au was thermally deposited as a top-transparent illumination contact. The poor performance of the device is mainly attributed to the poor transparency of the thin top-metal contact.