Electrical Contact Resistance in Graphite-Graphene contacts from ab initio methods

TL;DR

This study uses first-principles calculations to analyze the contact resistance in graphite-graphene interfaces, revealing how overlap length influences resistance and highlighting the potential for very low resistance in edge contacts.

Contribution

It provides a detailed ab initio analysis of contact resistance dependence on overlap length and compares top versus edge contact geometries.

Findings

Contact resistance saturates at transfer lengths around 20 Å.

Overlap greater than 20 Å can yield resistance below 100 Ω·μm.

Edge contacts are predicted to have very low contact resistance.

Abstract

We study the ballistic transmission and the contact resistance ($R_c$) of a graphite-graphene contact in a top contact geometry from first principles. We find that the calculated $R_c$'s depend on the amount of graphene-graphite overlap, but quickly saturate for transfer lengths of the order of 20 {\AA}. For contacts overlapping more than this transfer length, the $R_c$ can be lower than the 100 {\Omega}$\cdot${\mu}m mark. On the other hand, edge graphite-graphene contacts are expected to have very low contact resistance.