Molecular modeling and simulation of some efficient charge transfer materials using density functional theory

• Published in: Materials today communications 2020-03, Vol.22, p.100788, Article 100788
• Main Authors: Siddiqui, Shamoon Ahmad, Abdullah, Mohammad Margub
• Format: Article
• Language: English
• Subjects: Charge transfer materials; D-σ-A; Density functional theory; Molecular electronics
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2019.100788

[Display omitted] •Three charge transfer molecules were modeled using donor and acceptor moieties separated by insulating σ bridge.•TCNQ was chosen as electron acceptor moiety, while, Pentacene, Coronene and Diphenylpentacene were chosen as donor.•HOMO-LUMO gap for all three moieties was small enough for semiconducting charge transport.•HOMO-LUMO gap further shrinks with electric field in one direction and increased with electric field in opposite direction.•The response of HOMO-LUMO gap under electric field indicates that unidirectional charge transport is highly probable. Molecular simulation based on Density Functional Theory was performed on the three donor-bridge-acceptor molecular systems. We choose Tetracyanoquinodimethane (TCNQ) molecule as an electron acceptor and three different molecules namely, Pentacene, Coronene and Diphenylpentacene as an electron donor. The donor and acceptor moieties were connected with a σ bridge. After the modeling and optimization of these molecular systems, we performed electronic structure calculation. It has been observed that all these D-σ-A molecular systems have low HOMO-LUMO gap which suggests that there is a good possibility of charge transport between donor and acceptor moieties via σ bridge. To further explore the performance of these D-σ-A molecular systems, the electric field was applied along the –X and + X axis. It has been observed that HOMO-LUMO gap shrinks with the electric field along –X axis, however, with the electric field along + X axis, HOMO-LUMO gap was initially augmented and later on shrinks with the high electric field.