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

Titanium dioxide ( TiO 2 ) 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 TiO 2 layer, serving as the electron transport layer in CsPbBr 3 solar cells. This method is coupled with KCl, which supplies an ample quantity of K ions capable of diffusing into the CsPbBr 3 perovskite film during the annealing process. The inclusion of K ions significantly diminishes the solar cell hysteresis and enhances the crystalline quality of the perovskite material, thereby enhancing the performance of CsPbBr 3 solar cells. By implementing the TiO 2 and KCl treatments, we achieved an impressive efficiency of 9.49%. Furthermore, the device also exhibited excellent stability in air for 30 days. We introduced KCl as a buffer layer to improve the quality of the TiO 2 films, which was used as the electron transport layer in CsPbBr 3 perovskite solar cells. This strategic addition of K ions serves not only to alleviate hysteresis in the perovskite solar cells, but also to enhance the crystallinity of the perovskite material. These cells have achieved an impressive champion efficiency of 9.49%, while maintaining their performance for over 30 days in ambient conditions. [ABSTRACT FROM AUTHOR]