Improved FTO/NiO_x Interfaces for Inverted Planar Triple-Cation Perovskite Solar Cells

Front electrodes of fluorine-doped tin oxide (FTO) thin films and hole-transporting layers of nickel oxide thin films have been combined to fabricate 1.063 cm ² inverted planar solar cells with cesium-containing triple-cation perovskites as absorber layers. Using atmospheric pressure chemical vapor deposition, FTO layers were obtained with low sheet resistance, decreased root-mean-square roughness, increased transmission, and reduced optical haze values compared with a widely used commercial FTO substrate. Cell performance outperformed the equivalent cells fabricated using the commercial FTO. With full illumination under maximum power point tracking, a stabilized power conversion efficiency of 13.78% was obtained for the champion device.