▎ 摘　　要

Pt-graphene contacts are fabricated by atomic layer deposition (ALD) on H-2 and O-2 plasma functionalized graphene. The plasma functionalization of graphene enables the growth of uniform Pt layers on graphene by ALD and improves the Pt-graphene interaction, which results in a reduced Pt-graphene contact resistance. Devices created using a H-2 plasma treatment before Pt ALD perform considerably better than the ones created using O-2 plasma treatments (R-c = 0.4 +/- 0.2 k mu m and R-c = 1.2 +/- 0.1 k mu m, respectively). The lower performance of the O-2 plasma treatments is attributed to a less favorable Pt-graphene oxide interaction and the amorphization of graphene due to the O-2 plasma interaction. Supporting the latter, density functional theory calculations indicate that the CH groups created by a H-2 plasma treatment leave the -conjugation (by C-p(z) orbitals) of graphene largely intact, resulting in good in-plane and out-of-plane conductivity. The CO groups formed by an O-2 plasma treatment however disturb the C-p(z) character, deteriorating the in-plane conduction of graphene, despite the good out-of-plane conduction. The results indicate that the treatment of graphene by H-2 plasma is a straightforward approach to improve the ALD growth on graphene and reduce the Pt-graphene contact resistance.