AuCl<sub>3</sub> Doping for Reducing the Contact Resistance\nof the Aligned Carbon Nanotube–Au Heterojunction: Experimental\nResearch and First-Principles Calculation

The contact resistance between carbon nanotubes (CNTs)\nand metals\nis a key factor affecting their application. Traditional optimization\nmethods are often destructive in which it is difficult to achieve\nquantitative control. In this study, through in situ growth and directional\nrolling, CNT arrays arranged in parallel are obtained and formed side\ncontact structures with Au, selective doping of CNT–metal contact\nregions using 15 mM AuCl<sub>3</sub> resulted in a 43% decrease in\ncontact resistance, and the doping effect has good stability. Furthermore,\nthe band structure and projected density of states (PDOS) obtained\nby using density functional theory (DFT) are consistent with the experimental\nphenomenon. The method of reducing the contact resistance by doping\ndoes not destroy the structure of the material and can achieve quantitative\ncontrol. In addition, different combinations of dopants and metals\nshould be investigated to establish system schemes for the doping\nof heterojunctions.