Solvent effects and charge transfer states in organic photovoltaics: a time-dependent density functional theory study on the PCPDTBT:PCBM low band gap system
- Wayne State Univ., Detroit, MI (United States). Dept. of Chemistry
- Univ. of Houston, Houston, TX (United States). Dept. of Chemistry
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Long-range corrected time-dependent density functional theory has been used to study the solvent effect on excited state properties of PCPDTBT:PCBM (Poly[2,6-(4,4-dimethyl-4H-cyclopenta[2,1-b:3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)]:[6,6]-Phenyl-C61-butyric acid methyl ester) molecular system. A polarizable continuum model has been applied within the linear response (LR) and state-specific (SS) approaches to account for the dielectric environment. Here, the results show that the influence of the solvent depends on the nature of the excitations. For neutral excitonic states that are essentially localized on a single molecule, the solvent has little or no effects on the excitation energies according to both solvent schemes. On the other hand, for states with a significant amount of charge transfer (CT), the SS approach predicts a sufficient decline in the excitation energy as the dielectric constant increases so that the CT state can be stabilized to the lowest excited state, whereas the LR counterpart shows almost no change. The comparison of two solvent approaches is discussed.
- Research Organization:
- Los Alamos National Laboratory (LANL)
- Sponsoring Organization:
- National Science Foundation (NSF); USDOE Office of Science (SC)
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1483521
- Report Number(s):
- LA-UR-18-23122
- Journal Information:
- Journal of Photonics for Energy, Journal Name: Journal of Photonics for Energy Journal Issue: 3 Vol. 8; ISSN 1947-7988
- Publisher:
- SPIECopyright Statement
- Country of Publication:
- United States
- Language:
- English
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