Charge transport in polythiophene molecular device: DFT analysis

• Published in: Journal of molecular modeling Vol. 27; no. 3; p. 77
• Main Authors: Sirohi, Ankit, SanthiBhushan, Boddepalli, Srivastava, Anurag
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-03-2021; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Charge transport; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Density functional theory; Functional groups; Ions; Molecular electronics; Molecular Medicine; Original Paper; Polythiophene; Theoretical and Computational Chemistry; Transistors; Transport phenomena; NEGF; Molecular electronics; Charge transport; DFT; Polythiophene; HOMO-LUMO
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-021-04680-w

We report the charge transport phenomenon in polythiophene molecular device and the ways of controlling the nature of charge transport through the device. By using density functional theory (DFT) and non-equilibrium Green’s function (NEGF) formalisms, two ways of controlling the nature of charge transport have successfully been demonstrated by introducing conformational changes in the channel and applying external gate potential. Functional groups with negative mesomeric effect such as nitrous and carboxyl and positive mesomeric effect such as amino have been used as substituents as part of introducing conformational changes in the channel. The results indicate that the nature of charge transport in polythiophene molecular device can be changed from hole dominant to electron dominant and vice versa just by introducing minor conformational changes in the channel and by changing the polarity of external gate potential. Moreover, the negative differential resistance (NDR) behavior has been observed in amino-substituted thiophene device. These findings will be very useful in understanding the design of both
p
and
n
-type transistors out of same molecule for the next-generation molecular electronics.