Reduce the hysteresis effect with the PEIE interface dipole effect in the organic-inorganic hybrid perovskite CH3NH3PbI3-xClx solar cell

Abstract

Abstract Power conversion efficiency (PCE) of CH3NH3PbI3 perovskite solar cells has been developed rapidly, it reached the 22.1%. However, the anomalous hysteresis found in I-V measurements can cause an inaccurate estimation of the efficiency. In this article, we fabricated the ITO/PEDOT:PSS/CH3NH3PbI3-xClx/ PCBM/PEIE/Al structure perovskite solar cell, we inserted an interface layer of Polyethylenimine ethoxylated (PEIE) into solar cell device between the PCBM and aluminum (Al) electrode, the electrical filed induce photoluminescence (PL) quenching experiment and capacitance-voltage characteristic both demonstrate that the PEIE layer exists an interface dipole effect in the perovskite solar cell device, it can effectively reduce the hysteresis effect in the I-V measurement, and greatly increase the solar cell's efficiency from the 10.93%–14.46%. Utilizing the photoinduction dielectric response technology, we further found that the interface dipole effect increased the built-in electrical field, and enhanced the charge carrier transport properties, consequently, increased the short-circuit current (Jsc). On the other hand, the interface dipole effect decreased the concentration of defect on the CH3NH3PbI3-xClx surface, and made the charge injection barrier to increasing at the electrode and perovskite interface, leading to enhance the open-circuit voltage (Voc). In addition, the diminution of defect could further increase more effective electron transport channels, leading to the more charge carriers transport toward to the corresponding electrode, and increased the solar cell's Fill Factor (FF). Therefore, the addition PEIE interface layer in the perovskite solar cell not only can remove the hysteresis effect but also develop the high PCE perovskite solar cell. We hope the interface dipole effect as an effective methods can greatly promote and develop high efficiency and stable perovskite solar cells.