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Chemical Modification-Regulated Excited-State Dynamics and Charge Separation in TPA-C60 Donor-Acceptor Systems: A
Rui-Dong Zhao1, Rui-Bin Liu1, Gui-Lin Zhang1
1College of Chemistry and Material Science, Sichuan Normal University, Chengdu610068, China.
The Journal of Physical Chemistry. A
|July 27, 2026
Summary
Modifying donor conjugation and linker groups in TPA-C60 systems significantly impacts photoinduced charge-transfer dynamics. The -NH- linker enhances charge separation more effectively than -CH2-, crucial for organic solar cell development.
Area of Science:
- Materials Science
- Physical Chemistry
- Computational Chemistry
Background:
- Efficient organic solar cells (OSCs) rely on understanding and controlling photoinduced charge-transfer (CT) dynamics in donor-acceptor (D-A) systems.
- Tuning molecular structure is key to optimizing excited-state properties and charge separation in D-A materials.
Purpose of the Study:
- To systematically investigate the excited-state properties and nonadiabatic dynamics of four chemically modified TPA-C60 D-A systems.
- To analyze the effects of donor conjugation length and linker-group modification on optical absorption, relaxation dynamics, and CT behaviors.
Main Methods:
- Linear-response time-dependent density functional theory (LR-TDDFT) simulations.
- Nonadiabatic molecular dynamics (NAMD) simulations.
- Analysis of electron-hole density and fragment-based exciton properties.
Main Results:
- DA-C60 and DDA-C60 exhibit visible-light absorption and localized excitons, undergoing ultrafast relaxation.
- TPA-CH2-C60 and TPA-NH-C60 show broader UV-Vis absorption and pronounced D-A charge-transfer characteristics with slower relaxation.
- -NH- linker in TPA-NH-C60 promotes longer-lived charge-transfer excitons and greater electron-hole separation compared to the -CH2- linker.
Conclusions:
- Donor conjugation length and linker-group engineering effectively regulate excited-state relaxation pathways and CT behaviors in TPA-C60 systems.
- The findings provide insights for designing high-performance organic solar cell materials by controlling molecular structure.
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