1. Photoinduced charge transfer assisted through external electric field and ternary hydrogen bonding strategies.
- Author
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Guo, Huijie, Wang, Xinyue, Shen, Cong, Zhang, Meixia, Pullerits, Tõnu, and Song, Peng
- Abstract
• As F ext increase, the lowest ICT state exhibits a trend of decreasing excited states (S 10 → S 9 → S 8 → S 6). • The implementation of the ternary hydrogen bonding strategy resulted in a significant enhancement in the electron-attracting capability of the acceptor. • The hydrogen bond interaction of C7:PC 71 BM facilitates the formation of the ICT state (S 14), offering multiple potential pathways for charge separation. • F ext significantly enhances the hydrogen bond strength between C7:PC 71 BM and works synergistically with hydrogen bond to further affect the K CS of PTB7-Th:C7:PC 71 BM. Understanding the mechanisms governing interfacial charge transfer in photoactive layer is crucial for optimizing photogenerated charge separation efficiency. In this study, the interfacial charge transfer process is regulated by applying external electric field ( F ext) and ternary hydrogen bonding strategies. We observe significant changes in the excited state properties and charge transfer parameters at the interface under F ext conditions. This facilitates an in-depth exploration of the effects of F ext on the microscopic details of the interface at the molecular level. Implementing the ternary hydrogen bonding strategy significantly enhances the electron-attracting ability of fullerene. Comparative analysis of the PTB7-Th:PC 71 BM and PTB7-Th:C7:PC 71 BM systems under F ext = 0, reveals that the ternary hydrogen bonding strategy increases the charge transfer pathway and significantly improves the intermolecular charge separation rate (K CS). Additionally, we evaluated the relationship between hydrogen bond strength and F ext , demonstrating that F ext significantly enhances the hydrogen bond strength between C7:PC 71 BM. These studies provide deeper insights into the role of F ext and ternary hydrogen bonding strategies in charge transfer process, providing a valuable theoretical framework for designing more efficient organic solar cells (OSCs). [ABSTRACT FROM AUTHOR]
- Published
- 2024
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