Gu Miaoli, Zhang Jianjun, Kurganskii Ivan V, Poryvaev Artem S, Fedin Matvey V, Cheng Bei, Yu Jiaguo, Zhang Liuyang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, P. R. China.
Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 68 Jincheng Street, Wuhan, 430078, P. R. China.
Adv Mater. 2025 Feb;37(6):e2414803. doi: 10.1002/adma.202414803. Epub 2024 Dec 15.
Understanding charge carrier transfer at heterojunction interfaces is critical for advancing solar energy conversion technologies. This study utilizes continuous wave (CW), pulse, and time-resolved (TR) electron paramagnetic resonance (EPR) spectroscopy to explore the radical species formed at the TAPA (tris(4-aminophenyl)amine)-PDA (Terephthaldicarboxaldehyde)/ZnInS (TP/ZIS) heterojunction interface. CW and pulse EPR identify stable radical defects localized near the interface, accessible to water molecules. Time-resolved EPR reveals a photoinduced electron transfer from TP to ZIS, leading to the generation of spin-correlated radical pairs under light irradiation, signifying efficient charge carrier separation and spatial transfer within the S-scheme heterojunction. This electron transfer mechanism, confirmed through in situ X-ray photoelectron spectroscopy and femtosecond transient absorption spectroscopy, suppresses undesirable carrier recombination, extending charge carrier lifetimes. These findings provide novel insights into the transport direction of charge carriers at the S-scheme heterojunction interface, offering valuable guidance for designing highly efficient and stable organic-inorganic heterojunction photocatalysts for solar energy applications.
了解异质结界面处的电荷载流子转移对于推进太阳能转换技术至关重要。本研究利用连续波（CW）、脉冲和时间分辨（TR）电子顺磁共振（EPR）光谱来探索在TAPA（三（4-氨基苯基）胺）-PDA（对苯二甲醛）/ZnInS（TP/ZIS）异质结界面形成的自由基物种。连续波和脉冲EPR识别出位于界面附近、水分子可接触到的稳定自由基缺陷。时间分辨EPR揭示了光诱导电子从TP转移到ZIS，导致在光照下产生自旋相关的自由基对，这表明在S型异质结内电荷载流子有效分离和空间转移。通过原位X射线光电子能谱和飞秒瞬态吸收光谱证实的这种电子转移机制抑制了不希望的载流子复合，延长了电荷载流子寿命。这些发现为S型异质结界面处电荷载流子的传输方向提供了新的见解，为设计用于太阳能应用的高效稳定有机-无机异质结光催化剂提供了有价值的指导。
