Atomistic Insight into the Formation of Metal-Graphene One-Dimensional Contacts

Abstract

Motivated by the need to control the resistance of metal-graphene interfaces, we have simulated the structural and transport properties of edge contacts upon their formation. Our first-principles calculations reveal that the contacts evolve in a nontrivial way depending on the type of metal and the chemical contamination of the graphene edge. In particular, our results indicate that the origin of the low experimental resistance of chromium-graphene edge contacts is related to their weaker variation upon contamination and defect formation. In summary, by analyzing the distance dependence of the graphene-metal interaction and the relation between the reactivity and forces at the graphene edge, we shed new light on the mechanisms responsible for the diverse performance of experimentally fabricated graphene edge contacts.

Multi-scale approach to first-principles electron transport beyond 100 nm

“…[4][5][6][7][8][9][10][11][12] Quantum-chemical details are often critical for describing local electronic structure, chemical contacts (e.g. electrodes [13,14]) and electrostatics in realistic nano-electronic devices. This is especially clear in a context of one-atom-thick twodimensional (2D) devices, [7,15,16] where details on the atomic scale govern the electronic behavior.…”

Terahertz rectennas on flexible substrates based on one-dimensional metal-insulator-graphene diodes

“…Here, the graphene edge is in direct contact with the Ni and forms an ohmic contact. 19,24,25 At this point, graphene still covers the entire chip apart from directly below both metal contacts. The remaining graphene has been patterned into 6 µm long and 50 µm wide channels, before 100 nm thick aluminum (Al) has been deposited as antennas, transmission lines and contact pads.…”

Significant reduction in semiconductor interface resistance via interfacial atomic mixing

“…The nonequilibrium Green's function (NEGF) is often used to describe the structure-dependent charge transport [23]. Many works using NEGF combined with Landauer formula for conductance are conducted to study the transport across molecular junctions [24][25][26][27], nanotransistors [28,29], grain boundaries in two-dimensional materials [30], metal-semiconductor interfaces [31,32], metalmetal interfaces in magnetic multilayers [33][34][35][36] and semiconductor interfaces [37,38]. In particular, Bellotti et al investigated the carrier transport through semiconductor interfaces in the presence of positional and compositional disorders using NEGF and found that the disorder significantly impeded the coherent propagation of carriers through mul- tiple interfaces [37].…”