Tian Congcong, Sun Anxin, Zhuang Rongshan, Zheng Yiting, Wu Xueyun, Ouyang Beilin, Du Jiajun, Li Ziyi, Wu Xiling, Chen Jinling, Cai Jingyu, Hua Yong, Chen Chun-Chao
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China.
Yunnan Key Laboratory for Micro/Nano Materials & Technology, School of Materials and Energy, Yunnan University, Kunming, 650091, P. R. China.
Adv Mater. 2024 Sep;36(36):e2404797. doi: 10.1002/adma.202404797. Epub 2024 Jul 18.
2D perovskite passivation strategies effectively reduce defect-assisted carrier nonradiative recombination losses on the perovskite surface. Nonetheless, severe energy losses are causing by carrier thermalization, interfacial nonradiative recombination, and conduction band offset still persist at heterojunction perovskite/PCBM interfaces, which limits further performance enhancement of inverted heterojunction PSCs. Here, 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (5FTPP) is introduced between 3D/2D perovskite heterojunction and PCBM. Compared to tetraphenylporphyrin without electron-withdrawing fluoro-substituents, 5FTPP can self-assemble with PCBM at interface into donor-acceptor (D-A) complex with stronger supramolecular interaction and lower energy transfer losses. This rapid energy transfer from donor (5FTPP) to acceptor (PCBM) within femtosecond scale is demonstrated to enlarge hot carrier extraction rates and ranges, reducing thermalization losses. Furthermore, the incorporation of polystyrene derivative (PD) reinforces D-A interaction by inhibiting self-π-π stacking of 5FTPP, while fine-tuning conduction band offset and suppressing interfacial nonradiative recombination via Schottky barrier, dipole, and n-doping. Notably, the multidentate anchoring of PD-5FTPP with FA, Pb, and I mitigates the adverse effects of FA volatilization during thermal stress. Ultimately, devices with PD-5FTPP achieve a power conversion efficiency of 25.78% (certified: 25.36%), maintaining over 90% of initial efficiency after 1000 h of continuous illumination at the maximum power point (65 °C) under ISOS-L-2 protocol.
二维钙钛矿钝化策略有效地减少了钙钛矿表面缺陷辅助的载流子非辐射复合损失。尽管如此，载流子热化、界面非辐射复合以及导带偏移导致的严重能量损失在钙钛矿/PCBM异质结界面仍然存在，这限制了倒置异质结PSC的进一步性能提升。在此，在三维/二维钙钛矿异质结和PCBM之间引入了5,10,15,20-四（五氟苯基）卟啉（5FTPP）。与没有吸电子氟取代基的四苯基卟啉相比，5FTPP可以在界面处与PCBM自组装成具有更强超分子相互作用和更低能量转移损失的供体-受体（D-A）复合物。这种在飞秒尺度内从供体（5FTPP）到受体（PCBM）的快速能量转移被证明可以提高热载流子提取速率和范围，减少热化损失。此外，聚苯乙烯衍生物（PD）的加入通过抑制5FTPP的自π-π堆积增强了D-A相互作用，同时通过肖特基势垒、偶极子和n型掺杂微调导带偏移并抑制界面非辐射复合。值得注意的是，PD-5FTPP与FA、Pb和I的多齿锚固减轻了热应力期间FA挥发的不利影响。最终，具有PD-5FTPP的器件实现了25.78%的功率转换效率（认证：25.36%），在ISOS-L-2协议下于最大功率点（65°C）连续光照1000小时后保持超过90%的初始效率。
