Room Temperature Nanoparticulate Interfacial Layers for Perovskite Solar Cells via solvothermal synthesis

We present a solvothermal synthetic route to produce monodispersed CuO nanoparticles (NPs) in the range of 5-10 nm that can be used as hole selective interfacial layer between indium tin oxide (ITO) and perovskite active layer for p-i-n perovskite solar cells by a spin casting the dispersions at room temperature. The bottom electrode interface modification provided by spherical CuO-NPs at room temperature promotes the formation of high quality perovskite photoactive layers with large crystal size and strong optical absorption. Furthermore, it is shown that the nanoparticulate nature of the CuO hole transporting interfacial layer can be used to improve light manipulation within perovskite solar cell device structure. The corresponding p-i-n CH3NH3PbI3-based solar cells show high Voc values of 1.09 V, which is significantly higher compared to the Voc values obtained with conventional PEDOT:PSS hole selective contact based perovskite solar cells.