Intrinsic current–voltage characteristics of metal-carbon nanotube networks: A first-principles study

• Transport properties are strongly dependent on the connecting metal atoms.
• Inert Au do not have any noteworthy enhancement function on SWNT systems.
• Metal Cr, Li and Au have different behaviors on different SWNT systems.
• NDR feature have been found in Cr and Li in inter-tube model.

The interconnections involving metal atoms in single-walled carbon nanotube (SWNT) networks are crucial for building nanoscaled devices. The influence of the metal-(η6-SWNT) interconnects in the electrical conductivity of SWNT film have been reported in recent experiments [X. Tian et al. Nano lett. 2014,14,3930]. Using non-equilibrium Green's function with density function theory, we performed theoretical calculations on the electron transport properties of (Cr, Li, Au)-SWNT systems. We revealed the roles of transition metal Cr, alkalis metal Li and inert metal Au in improving the electrical conductance of metal-SWNT systems. Our calculated results show that transport properties along the inter-tube direction are strongly dependent on the connecting metal atoms varying over many orders of magnitudes. Gold atoms fail to enhance the electrical conductance of SWNT systems. Meanwhile, negative differential resistances are demonstrated in semiconducting inter-tube models, which would have potential applications in the electronic device. Our results provide a promising way to optimize the performance of SWNT based networks.

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