Electrical contact resistance in graphite-graphene contacts from ab initio methods.

We study the ballistic transmission and the contact resistance (R ) of a graphite-graphene contact in a top contact geometry from first principles. We find that the calculated R 's depend on the amount of graphene-graphite overlap, but quickly saturate for transfer lengths of the order of a few tens of Å. For contacts overlapping more than this transfer length, the R can be lower than the 100 [Formula: see text] mark. On the other hand, edge graphite-graphene contacts are expected to have very low contact resistance.