Modification of Interface with APMS Molecules for the Fabrication of Highly Efficient and Long-Term Stable Perovskite Solar Cells

The surface morphology of perovskite material is critical for high-efficiency perovskite solar cells (PSCs), due to its high sensitivity to humidity. The boundaries of the interface layer, ion migration into the cell, and defects on the film surface negatively affect the efficiency and stability of PSCs. Furthermore, defects on the surface and at the grain boundaries of these films also have a negative impact on charge recombination. In this study, the fabrication of cells using 3-aminopropyltrimethoxysilane (APMS), a silane coupling agent, as a small molecule to passivate defects in a TiO2 and perovskite film was achieved. By improving the crystallinity and uniformity of perovskite grains, the power conversion efficiency for solution-treated planar heterojunction solar cells was increased from 8.95% to 9.77% with less hysteresis. In conclusion, it was determined that APMS small molecules improve the surface properties of perovskite cells, enhancing cell performance and offering a potential solution to one of their most significant problems: stability.