Nickel Oxide/Graphene Oxide (NiO/GO) as Double Hole Transport Layer in Perovskite Solar Cell

The hole transport layer is one of the most crucial parts of the perovskite solar cell. Recently, some studies have improved perovskite solar cell performance by modifying the surface of the hole transport layer using double fabrication of inorganic-organic materials. Their studies generate higher power conversion efficiency than inorganic materials but have not generated good stability. Therefore, this study aims to develop a double-hole transport layer using nickel oxide (NiO) and graphene oxide (GO) to improve the perovskite solar cells performance. The experiment utilizes the spin-coating method to observe the effect of combining NiO and GO in perovskite solar cells. The experimental results showed that the double hole transport layers produce better power conversion efficiency of 15.3% compared to single-layer NiO. The double holes can smoothen the holes of the perovskite interface layer and cause molecular uniformity to reduce recombination. In addition, NiO/GO surfaces show better stability to environmental conditions.