Surface Modification of TiO2 for High Performance in all Inorganic Perovskite Solar Cells

Abstract

Titanium dioxide (TiO[Formula: see text] is a commonly employed electron transport layer in perovskite solar cells (PSCs) due to its exceptional attributes such as high mobility, a wide bandgap and remarkable stability against moisture and high temperatures. This holds particularly true for inorganic PSCs. Nevertheless, the substantial hysteresis and elevated trap defect levels following annealing present challenges to enhance the efficiency of the PSCs. Herein, we proposed a chemical bath deposition (CBD) method to fabricate the TiO2 layer, serving as the electron transport layer in CsPbBr3 solar cells. This method is coupled with KCl, which supplies an ample quantity of [Formula: see text] ions capable of diffusing into the CsPbBr3 perovskite film during the annealing process. The inclusion of [Formula: see text] ions significantly diminishes the solar cell hysteresis and enhances the crystalline quality of the perovskite material, thereby enhancing the performance of CsPbBr3 solar cells. By implementing the TiO2 and KCl treatments, we achieved an impressive efficiency of 9.49%. Furthermore, the device also exhibited excellent stability in air for 30 days.