Grain boundaries in organic–inorganic halide perovskite solar cells (PSCs) have been found to be detrimental to the photovoltaic performance of devices. Here, we develop a unique approach to overcome this problem by modifying the edges of perovskite grain boundaries with flakes of high-mobility two-dimensional (2D) materials via a convenient solution process. A synergistic effect between the 2D flakes and perovskite grain boundaries is observed for the first time, which can significantly enhance the performance of PSCs. We find that the 2D flakes can conduct holes from the grain boundaries to the hole transport layers in PSCs, thereby making hole channels in the grain boundaries of the devices. Hence, 2D flakes with high carrier mobilities and short distances to grain boundaries can induce a more pronounced performance enhancement of the devices. This work presents a cost-effective strategy for improving the performance of PSCs by using high-mobility 2D materials.

已经发现有机-无机卤化物钙钛矿太阳能电池（PSC）的晶界不利于器件的光伏性能。在这里，我们开发了一种独特的方法来克服此问题，方法是通过方便的固溶过程，用高迁移率二维（2D）材料薄片修饰钙钛矿晶界的边缘。首次观察到二维薄片与钙钛矿晶界之间的协同效应，这可以显着增强PSC的性能。我们发现二维薄片可以将空穴从晶界传导到PSC中的空穴传输层，从而在器件的晶界中形成空穴通道。因此，具有高载流子迁移率和到晶界的短距离的2D薄片可以引起器件性能的显着提高。