21 May 2018 Solvent effects and charge transfer states in organic photovoltaics: a time-dependent density functional theory study on the PCPDTBT:PCBM low band gap system
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Abstract
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. 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.
© 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Kangmin Liu, Kangmin Liu, Hao Li, Hao Li, Sergei Tretiak, Sergei Tretiak, Vladimir Chernyak, Vladimir Chernyak, "Solvent effects and charge transfer states in organic photovoltaics: a time-dependent density functional theory study on the PCPDTBT:PCBM low band gap system," Journal of Photonics for Energy 8(3), 032215 (21 May 2018). https://doi.org/10.1117/1.JPE.8.032215 . Submission: Received: 23 January 2018; Accepted: 20 April 2018
Received: 23 January 2018; Accepted: 20 April 2018; Published: 21 May 2018
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