Effect of surface treatment of sputtered nickel oxide in inverted perovskite solar cells

Nickel oxide (NiOx) is promising hole transport material for efficient and stable lead halide perovskite solar cell (PSC) due to its promising optoelectronic properties and superior moisture resistivity. Herein, we investigate the effect of surface treatment of sputtered NiOx film using ethanol (NiOx-EtOH) in device parameters of PSC. Ethanol treatment of NiOx facilitates the growth of high-quality perovskite film (larger grain size, better crystallinity, and faster carrier injection). The device with NiOx-EtOH demonstrated the champion power conversion efficiency of ∼13.52% (with open circuit voltage (VOC) ∼1.075 V) of 1 cm2 large-area device. While the device with pristine NiOx has a device efficiency of 11.78% (with VOC ∼0.99 V). This report corroborates that the PSC with NiOx-EtOH improves device performance owing to hydrophilicity, defect passivation of sputtered NiOx surface, and attenuation of recombination in the perovskite bulk.