Journal of Materials Science Research and Reviews

Charge Transport Enhancement in Anthracene Molecular Junction: Density Functional Theory Studies

Kassim L. Ibrahim *

Physics Department, Kano University of Science and Technology, Wudil, Nigeria.

G. Babaji

Department of Physics, Bayero University Kano, Nigeria.

A. M. Nura

Department of Physics, Bayero University Kano, Nigeria.

*Author to whom correspondence should be addressed.

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Abstract

Device miniaturization and a desire to add some functionality for the next-generation electronic circuits have prompted the research community into a single molecule electronics. Here, we analyzed anthracene molecules coupled to Au electrodes through anchor groups. By using density functional theorem (DFT) in combination with non-equilibrium Green’s functional (NEGF) formalism, we investigated the frontier molecular orbitals (MOs) and charge transport nature of the junction by giving special consideration to the anchoring groups (NH₂, S, CN and SH), chemical impurity doping (B, N and NB) and side groups (-CH₃, -NH₂, and -NO₂). The results shows that the MOs can vary depending upon the substituents or dopants used. NB-doped has the lowest HOMO-LUMO gap of 0.25eV, and is expected to be more stable. We also observed that charge transport can be p-type or n-type depending on the anchor materials used. It is found that the amines anchor group have a higher conductance (i.e T(E) ≈ 0.98) for an anthracene molecular junctions (MJs). These findings can be very helpful in understanding and fabrication of either n-type or p-typed high conductive single molecule electronic components.

Keywords: Anthracene, charge transport, DFT, HOMO-LUMO, NEGF, transmission

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