Photoinduced charge transfer in two-photon absorption

The visual method is used to theoretically discuss the influence of different external electric fields on the photo-induced charge transfer of the donor-bridge-acceptor (D-B-A) system in the two-photon absorption (TPA). We dynamically observe the transition process in different spatial dimensions. The final results show that the external electric field can manipulate the orientation and type of intermolecular charge transfer in the TPA process of the D-B-A system. The changes in the proportions of sequential charge transfer and super-exchange charge transfer in TPA provide a strong proof for the conclusion. This non-monotonic change has theoretically deepened our understanding of the charge transfer characteristics in TPA, and we have a further understanding of the optical properties of the D-B-A system.