p-Type CuCrO2 particulate films as the hole transporting layer for CH3NH3PbI3 perovskite solar cells†
CuCrO2 with a crystal structure of delafossite is a promising material as a transparent conducting oxide. It shows unique properties, for example, wide band gap, good chemical stability, and p-type carrier transporting character. The oxide layers with delafossite structure have been suggested as hole transporting materials for organic–inorganic CH3NH3PbI3 perovskite solar cells. In this study, we fabricated inverted (p–i–n) type planar perovskite solar cells with CuCrO2 nanoparticles synthesized by the hydrothermal method and their films were formed by spin-coating without any further heat treatment. The champion device gave a 13.1% of power conversion efficiency and CuCrO2 based devices show improved stability in ambient air compared with the standard PEDOT:PSS based perovskite solar cells.