Cu <sub/>12</sub> Sb <sub/>4</sub> S <sub/>13</sub> Quantum Dots with Ligand Exchange as Hole Transport Materials in All-Inorganic Perovskite CsPbI <sub/>3</sub> Quantum Dot Solar Cells

摘要： Perovskite solar cells (PSCs) have developed rapidly in the past ten years. However, they are faced with huge challenge on stability improvement because of the volatile organic component in light absorption and hole transporting layer. Herein, we fabricate all inorganic PSCs with the structure of FTO/c-TiO2/m-TiO2/CsPbI3 quantum dots (QDs)/Cu12Sb4S13 QDs/Au to improve device stability. To enhance the photovoltaic performance of PSCs, the surface oleylamine ligands of Cu12Sb4S13 QDs with 3-mercaptopropionic acid are exchanged, as the enhanced electronic coupling and reduced bandgap are realized after the ligands exchange. Cu12Sb4S13 QDs based PSCs exhibit a PCE of 10.02%, approaching to the Spiro-MeOTAD based PSCs (12.14%). A high short-circuit current density of 18.28 mA*cm-2 is achieved because of the enhanced light absorption and excellent hole extraction ability of Cu12Sb4S13 QDs. Moreover, Cu12Sb4S13 QDs based PSCs exhibit the improved long-term stability and retain 94% of their initial PCE after stored in ambient air after 360 h.