Interfacial engineering is essential for making highly efficient and stable solar cells and minimizing energetic losses at interfaces. ITO modification via self-assembled monolayers (SAM) is a very useful method to tune work function, improve the cell performance and stability in photovoltaic devices. In this study, for the first time, boronic acid based Fluorine terminated SAM molecules used to modify ITO surface in planar perovskite solar cells. The results showed that SAM treatment reduced the work function of ITO, significantly enhanced cell performance and passivated trap states in ITO/PEDOT:PSS interface. Improvements in long term stability of cells have also been tested for thirty days and found that SAM modified cells conserved %80 of its first day efficiency. Our results represent a treatment route to achieve hysteresis free, stable and highly efficient (% 16) planar perovskite solar cells.