Poly(triarylamine) (PTAA) is typically used as a hole transport layer due to its suitable energy band alignment with the perovskite layer, but its poor permeability to perovskite precursors can easily lead to buried interface defects. In light of this, Professor Li Xuanhua from Northwestern Polytechnical University and colleagues published a paper in Nano Energy, titled “π-Interactions suppression of buried interface defects for efficient and stable inverted perovskite solar cells”. This study proposes a molecular bridging strategy using a special π-interaction molecule, 2,4,6-tris(4-aminophenyl)-s-triazine (TAPT), to bridge PTAA and the perovskite layer. The amino groups of TAPT can form H-π bonds with the phenyl rings in PTAA, tightly binding them and thereby fixing the fractures in PTAA and reducing defect sites, while the triazine ring of TAPT can interact with uncoordinated Pb2+, forming π-Pb2+ bonds, thus passivating Pb2+ defects. Furthermore, TAPT helps achieve a pinhole-free buried interface, enhancing carrier transport across the interface and suppressing non-radiative recombination at the interface. Ultimately, devices containing TAPT achieved a champion efficiency of 24.57%. Devices with TAPT significantly improved operational and thermal stability, maintaining 89.7% of initial efficiency after 1500 hours of maximum power point tracking and 91.9% of initial efficiency after 1065 hours of thermal treatment at 85℃. This method emphasizes the crucial role of buried interface π-interactions in the development of efficient and stable perovskite solar cells.
Original link:https://doi.org/10.1016/j.nanoen.2023.108883
Original link:https://doi.org/10.1016/j.nanoen.2023.108883
