Theoretical estimation of the dissociation energy of CT states at the acenes/C60 interfaces using fragmental-based ALMO method
Publication date: Available online 17 July 2018Source: Computational and Theoretical ChemistryAuthor(s): Xinbo Yang, Wenliang Wang, Shiwei YinAbstractThe dissociated energy (ECTdiss) of charge-transfer state at the DA interaction is a crucial parameter to determine the efficiency of organic solar cells. The ΔSCF-liked absolutely-localized molecular method (ALMO) combining with DFT is applied to investigate ECTdissof the lowest CT with prototype oligoacenes/C60 models. The lowest CT energies obtained from ALMO coupled with various exchange-correlation (XC) functionals behave a correct 1/d asymptotic feature. Although CT energies show XC functional dependent feature, ECTdissbehaves XC functional independence and correct 1/d asymptotic character. These mean that ALMO can well describe the electrostatic interactions between positive donor and negative acceptor. ALMO also provide an XC-independent method to evaluate ECTdiss. The condensed-phase ECTdissalso are simply studied by ALMO coupled with polarizable continuum model. The results of ECTdissdemonstrate that increasing the conjugation-length, high-dielectric constant, and adjusting molecular packing to control the electrostatic polarization are effective methods to dissociate the lowest CT into free electron and hole carriers.Graphical abstract
Source: Computational and Theoretical Chemistry - Category: Chemistry Source Type: research