Exploring the effect of electric field on charge-transfer states at non-fullerene D/A interface

Abstract

Using Marcus theory, the electric-field-dependent charge-separation dynamics of non-fullerene acceptors D/A heterojunctions are simulated. On the D/A interface, the excited-state characteristics show obvious differences under different electric field intensities, providing microscopic details of the non-fullerene D/A interface at the atomic level. For different electric field conditions, so the calculated reorganization energy ranges from 0.97 to 1 eV. By comparing other charge transfer parameters of this system, it was found that the reorganization energy mainly determines the charge-transfer rate. The results show that the charge transfer rate does exhibit a variation that depends on the electric field intensity and is consistent with the variation in the Marcus inverted region. By evaluating the rate of charge separation/recombination, it is judged that its charge separation shows significant advantages, and the trifurcated structure of the molecule also provides multiple charge transfer paths for charge separation, which contributes to the charge generation mechanism.