Ab Initio Study of Iodine-Doped Carbon Nanotube Conductors

The widespread use of copper in power and data cabling for aircraft, ships, and ground vehicles imposes significant mass penalties and limits cable ampacity. Experimental research has suggested that iodine-doped carbon nanotubes (CNTs) can serve as energy efficient replacements for copper in mass sensitive cabling applications. The high computational costs of ab initio modeling have limited complimentary modeling research on the development of high specific conductance materials. In recent research, the authors have applied two modeling assumptions, single zeta basis sets and approximate geometric models of the CNT junction structures, to allow an order of magnitude increase in the atom count used to model iodine-doped CNT conductors. This permits the ab initio study of dopant concentration and dopant distribution effects, and the development of a fully quantum based nanowire model which may be compared directly with the results of macroscale experiments. The accuracy of the modeling assumptions is supported by comparisons of ballistic conductance calculations with known quantum solutions and by comparison of the nanowire performance predictions with published experimental data. The validated formulation offers important insights on dopant distribution effects and conduction mechanisms not amenable to direct experimental measurement.