Department of Materials Science & Metallurgy: Research paper of the month

Department of Materials Science & Metallurgy

Research paper of the month

September 2015 - A computational study of the quantum transport properties of a Cu-CNT composite

Using the non-equilibrium Green’s function approach, the transport properties of a Cu–CNT composite have been determined as a function of CNT density, chirality and alignment to the bias potential. A model is used in which the CNT is fully embedded within the Cu matrix. The electrical conductance is found to be highest when the axial direction of the CNT is along the transport direction. Compared to pure Cu the reduced conductance is attributed to localized charge exchange between the CNT and the metal surface that raises the potential barrier at the interface. The chirality of the CNT does not appear have a major effect on the conductance at least for the CNTs and densities considered here. The results could play an important role in guiding the design and fabrication of Cu–CNT composites for optimal performance. Understanding and controlling the interface between the Cu and CNT in the bulk composite is critical for maximising the electrical performance of this promising new generation of materials.                  

Figure: Electron difference density maps through cross-sections of the scattering region (upper) and the average electrostatic difference potential along the transport direction (lower) for the three Cu-CNT (6,6) composite orientations considered. The peak positions are indicated with red arrows to highlight the good correspondence between the upper and lower panel.

M. Ghorbani-Asl, P.D. Bristowe and K. Koziol, "A computational study of the quantum transport properties of a Cu–CNT composite", Phys. Chem. Chem. Phys., 17 (2015) 18273-18277  

doi: 10.1039/c5cp01470k