Physical Mechanism of Photoinduced Charge Transfer in One- and Two-Photon Absorption in D-D-π-A Systems

• Main Authors: Xinyue Wang, Di Wang, Jia Li, Meixia Zhang, Peng Song
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Materials
• Subjects: one-photon absorption; two-photon absorption; absorption cross-section; charge transfer
• Online Access: https://www.mdpi.com/1996-1944/14/14/3925

The photoinduced charge transfer process of a D-π-A molecule (W1) and three D-D-π-A molecules (WS5–WS7) with triphenylamine as a donor was studied theoretically. D-D-π-A molecules are formed by inserting donors between the triphenylamine and π-linker (π-bridge) on the base of the W1 molecule. The results showed that donor insertion resulted in a red shift in the absorption spectrum, and the absorption intensity increased to a certain extent. A visualization method was used to observe the charge transfer of the four molecules in the process of one- and two-photon absorption (TPA). The local excitation enhanced charge transfer excitation in the TPA process was analyzed and discussed, and the insertion of the thiazolo[5,4-d]thiazole donor showed the largest TPA cross-section. This work contributed to the profound understanding of D-D-π-A molecules and the design of large cross-section TPA molecules.