Reconfiguration toward Self‐Assembled Monolayer Passivation for High‐Performance Perovskite Solar Cells. Issue 3 (29th November 2022) - Chen, Zijing
Abstract: Self‐assembled monolayers (SAMs) with unique ordered structures and varied anchoring groups have emerged as an excellent interfacial strategy for perovskite solar cells (PSCs). Herein, 3‐carboxypropyl‐triphenyl phosphonium bromide with the participation of the fullerene derivative [6, 6]‐phenyl‐C61 ‐butyric acid (PCBA) as functionalized C‐PCBA SAM, is introduced to stably modify the TiO2 /perovskite interface. In the meantime, with strong fullerene cage–iodide interaction, ordered C‐PCBA SAM can passivate interfacial defects and improve the electron transportation. A high efficiency of 24.8% and stabilized power output of 23.9%, are achieved with negligible hysteresis, which is among the best performances for TiO2 planar PSCs. This modified cell also exhibits significantly improved stabilities under different testing conditions; non‐encapsulated devices can maintain 95% of initial efficiency after 1000 h thermal stability testing at 85 °C and 85% after 700 h continuous illumination (≈100 mW cm −2 ) and maximum‐power‐point tracking. This work provides valuable inspiration for developing highly efficient and stable PSCs by using a convenient SAM reconfiguration strategy. Abstract : A functionalized interfacial passivation layer, a kind of self‐assembled monolayer, is developed to modify TiO2 /perovskite interfaces. With the synergistic contribution of defect passivation and charge transfer improvement, as high as 24.8% efficiency with negligible hysteresis is achieved for TiO2 ‐based planer perovskite solar cells (PSCs), meanwhile, the perovskite films exhibit excellent moisture stability and the PSC devices have excellent operational stability.