Study on the Influence of External Electric Field Control and Vibrational Quantum Effect on the Charge Separation Mechanism in Fullerene-Based Systems.

Abstract

Based on the DCV-C₆₀ system of fullerene acceptor organic solar cell active materials, the charge transfer process of D-A type molecular materials under the action of an external electric field (F_ext) was explored. Within the range of electric field application, the excited state characteristics exhibit certain regular changes. Based on reducing the excitation energy, the excitation mode shows a trend of developing toward low excited states. The effect of solvent polarity on the stability and reorganization energy of the charge transfer state was investigated. The dependence of charge separation parameters on specific molecular structures within the electric field range was studied, proving that the electric field set along the electron transfer direction can indeed accelerate charge separation. The influence of vibrational modes on the charge separation process was studied, and the results showed that the vibrational quantum tunneling effect significantly promoted the charge separation. Therefore, considering the vibrational excitation effect and the perturbation of the nuclear-electron interaction is crucial for more accurate simulation of the electron-vibration coupling process in the excited state.