Organic–inorganic perovskite solar cells suffer from low stability and the solution methods used for fabrication are not always scalable or reproducible. Perovskite solar cells with inorganic absorber layers and charge transport layers are an attractive route towards achieving long-term stability. Additionally, resistive evaporation allows for scalable and reproducible thin films. CsPbBr \({}_3\) active layers of varying thicknesses are prepared using the multi-step sequential resistive evaporation of CsBr and PbBr \({}_2\) . Charge transport layers of tin oxide and cuprous oxide are prepared using resistive evaporation of the metal followed by thermal oxidation to form a metal oxide. These layers are combined to form an all-inorganic, solvent-free solar cell. The optimal device has a CsPbBr \({}_3\) thickness of 775 nm, and has a power conversion efficiency, open circuit voltage, short circuit current density, and fill factor of 3.0%, 1.037 V, 5.4 mA/cm \({}^2\) , and 54%, respectively, when measured in the forward direction. Time-resolved current measurements are used to show electronic and ionic responses under different biasing conditions. Impedance spectroscopy is used along with a new equivalent circuit to resolve different contributions to the electrical response of the devices. This work demonstrates a novel single-method vacuum process for fabricating all-inorganic perovskite solar cells.
