Surface-Induced Hybridization between Graphene and Titanium

Abstract

Carbon-based materials such as graphene sheets and carbon nanotubes have inspired a broad range of applications ranging from high-speed flexible electronics all the way to ultrastrong membranes. However, many of these applications are limited by the complex interactions between carbon-based materials and metals. In this work, we experimentally investigate the structural interactions between graphene and transition metals such as palladium (Pd) and titanium (Ti), which have been confirmed by density functional simulations. We find that the adsorption of titanium on graphene is more energetically favorable than in the case of most metals, and density functional theory shows that a surface induced p-d hybridization occurs between atomic carbon and titanium orbitals. This strong affinity between the two materials results in a short-range ordered crystalline deposition on top of graphene as well as chemical modifications to graphene as seen by Raman and X-ray photoemission spectroscopy (XPS). This induced hybridization is interface-specific and has major consequences for contacting graphene-nanoelectronic devices as well as applications toward metal-induced chemical functionalization of graphene.

Influence of interface interaction on the moiré superstructures of graphene on transition-metal substrates

“…Previous studies illustrated that the strong interfacial interactions between graphene and transition metal substrates involve hybridization between C p orbitals and metal d orbitals, especially the hybridization between the C 2p z orbital and the metal d z 2 orbital. 15,16,[24][25][26][27][28] The partial density of states (PDOS) of C atoms (2p z orbital) and Re atoms (5d z 2 orbital) at the at region and hump (labeled in Fig. 5a) helped to understand the charge transfer behavior between C atoms and Re atoms in the at region.…”

Towards an optimal contact metal for CNTFETs

“…These large values of the self-energy should not be confused with the shift of the CNT bands, which is comparable to that in graphene. 34,35 The former characterizes the effect of a metal on the embedded CNT; the latter characterizes the changes of a CNT subsystem due to the interaction with the metal.…”

Spin and charge transport in graphene-based spin transport devices with Co/MgO spin injection and spin detection electrodes

“…By now, there are only few studies reporting epitaxial-like growth of materials on graphene, e.g. EuO [48] or Ti [69]. The hydrocarbon contaminations from the lithography step and the clustering of many materials on top of graphene are important issues for graphene-based spin transport devices because both can reduce the quality of the insulating oxide barrier between graphene and the ferromagnetic electrodes.…”