Role of annealing temperature of nickel oxide (NiOx) as hole transport layer in work function alignment with perovskite

Use of inorganic charge transport layer has demonstrated relatively stable perovskite solar cells (PSCs). NiOx is the most widely used inorganic hole transport layer in inverted PSCs and different techniques and doping in this layer have been reported to improve the performance of these devices. This manuscript describes the synthesis of NiOx thin film which act as hole transport layer on glass substrate at the initial stage and PSC devices were fabricated at the secondary stage. Effect of post deposition annealing temperature on the composition, tuning of the work function and aligning it with perovskite work function increase the hole transport efficiency and improve the open circuit voltage of devices from 0.96 to 1.08 V is reported. Ultraviolet photoelectron spectroscopy results were used to check the change in work function and X-ray photoelectron spectroscopy to probe the underlying reason for improvement of devices are also included. The charge transfer efficiency is checked by the results of time resolved photoluminescence spectra is also given. Devices with NiOx as hole transport layer and ZnSe as electron transport layer are also described and performance of devices is also included in this manuscript.