Interface Modification with Inorganic Metal Salt for High Efficiency Perovskite Solar Cells

Interface modification has emerged as a highly effective strategy for achieving the synergistic optimization of surface defects of SnO2, film quality of perovskite, and their interfacial energy level matching, thereby contributing to the photovoltaic performance and long-term stability of perovskite solar cells (PSCs). Herein, we introduced SbCl3 into the SnO2/MAPbI(3) interface. This approach capitalizes on the difference in electronegativity and the similarity in ionic radii between Sn and Sb, inducing an interaction between Sn and O atoms on the SnO2 surface with Sb from SbCl3. The interaction results in an excellent SnO2/MAPbI(3) interface with fewer defects and better energy level alignment. Moreover, high-quality perovskite films with fewer bulk defects were achieved due to the beneficial effects of Cl- anions that passivate uncoordinated Pb2+ defects and promote MAPbI(3) crystallization. As a result, MAPbI(3) PSCs with SbCl3 modification prepared in a full open-air environment demonstrated a PCE of 20.69% along with enhanced stability. This research highlights the substantial potential of incorporating SbCl3 into the SnO2/perovskite interface as a promising approach for enhancing both the efficiency and stability of planar PSCs.