Zhu Siyuan, Kang Dawei, Liu Zhiyu, Zhang Meixia, Ding Yong, Song Peng
Department of Physics, Liaoning University, Shenyang 110036, People's Republic of China.
J Phys Chem A. 2022 Jun 16;126(23):3669-3679. doi: 10.1021/acs.jpca.2c01643. Epub 2022 Jun 1.
This article theoretically studies the photoinduced charge transfer (CT) of rigid D-B-A molecules in two-photon absorption (TPA) adjusted by the external electric fields. Using a visualization method, the dynamic changes of light-induced CT in different channels of TPA are presented through a two-dimensional (2D) transition density matrix and a three-dimensional (3D) charge different density. Here, we prove the controllability of TPA on CT under the induction of a strong electric field. Adjusting the field direction and intensity significantly affects the position of the strong absorption peak in the TPA spectra, thereby further changing the electron-hole coherence length and the degree of dispersion. Our results can promote the recognition of the optical properties of the D-B-A system in synthetic molecules and provide an idea for increasing the proportion of excited states for CT in the molecule.
本文从理论上研究了外部电场调节下刚性D - B - A分子在双光子吸收（TPA）过程中的光诱导电荷转移（CT）。采用可视化方法，通过二维（2D）跃迁密度矩阵和三维（3D）电荷差异密度呈现了TPA不同通道中光诱导CT的动态变化。在此，我们证明了在强电场诱导下TPA对CT的可控性。调整场方向和强度会显著影响TPA光谱中强吸收峰的位置，从而进一步改变电子 - 空穴相干长度和色散程度。我们的结果能够促进对合成分子中D - B - A体系光学性质的认识，并为提高分子中CT激发态的比例提供思路。
