Novel nanostructured electron transport compact layer for efficient and large-area perovskite solar cells using acidic treatment of titanium layer

A new method for the deposition of a pinhole-free compact layer of TiO2 is introduced for the development of efficient perovskite solar cells. Acidic treatment of titanium layer (ATTL), deposited by rotational magnetron sputtering, presents a compact pinhole-free TiO2 thin film. Deposition of a compact TiO2 thin film on fluorine-doped tin oxide layers by ATTL did not change the surface roughness. To compare the introduced method, perovskite solar cell devices were fabricated and studied using different methods for the deposition of the TiO2 compact layers, which were used as common compact layer deposition methods. The ATTL method proposed considerable photovoltaic enhancement of perovskite solar cell performance (at least 22% enhancement in this work) by reducing the pinholes and sheet resistance of the TiO2 thin film. The improvement in the open-circuit voltage and the fill factor of the prepared devices using the ATTL method strongly confirmed the nature of the deposited pinhole-free TiO2 thin film. This method is shown to be an appropriate route for the reliable large-scale deposition of TiO2 compact layers.