Potassium oleate as an effective interface modifier for defect passivation in planar perovskite solar cells

Abstract

As a typical of the next generation photovoltaic technology, perovskite solar cells (PSCs) have attracted extensive attention in industry and academia because of their outstanding excellent performance and unprecedented growing efficiency. However, commercial applications of PSCs require further improvements in efficiency and stability, and the defects and its induced non-radiation loss become the research hotspots. Herein, potassium oleate (KOA) as an effective modifier is introduced at the interface of perovskite/spiro. The K[Formula: see text] ions of KOA can penetrate into the perovskite bulk to fill the positive charge vacancy; the-COO[Formula: see text] group of KOA can coordinate with Pb[Formula: see text] and passivate defects; the hydrophobic long chain olefins of KOA can cover on perovskite, and thus, ameliorate the environmental stability of the devices. As a result, the multi-functional KOA-modified PSC achieves an impressive efficiency of 23.22%, along with high open circuit voltage ([Formula: see text] of 1.16 V.