Healing the Defective Surface for High-Efficiency and Stable All-Inorganic Perovskite Solar Cells
【摘要】：The importance of controlling interface energetics is gradually ascensive owing to the soft nature of perovskite lattice, which induces substantial defects and energy barrier for charge recombination within a PSC. With the aim to effectively heal the defective surface, we have conducted the interface engineering by incorporating 2 D materials into the allinorganic perovskite solar cells(PSCs). Arising from the fabrication of WS_2/CsPbBr_3 van der Waals heterostructure(playing a role of "lubricant" between ETL and perovskite), the tensile strain in the perovskite film is released for a uniform perovskite with low defect density and high activation energy for ion migration, which significantly improves the device voltage up to 1.70 V for CsPbBr_3 PSC. In addition, p-type charge transfer doped(NiCo)_(1-y) Fe_y O_x-GO is further employed as an excellent hole booster owing to the spontaneous electron transfer from edged oxygencontaining functional groups to(NiCo)_(1-y)Fe_yO_x. As a result, the inorganic CsPbIBr2 PSC presents the highest efficiency of 10.95% in corresponding carbon-electrode based devices under one standard sun owing to the eliminated paradox between charge extraction and charge localization in GO surface.