Field effect doping of graphene in metal|dielectric|graphene heterostructures: a model based upon first-principles calculations

Abstract

We study how the Fermi energy of a graphene monolayer separated from a conducting substrate by a dielectric spacer depends on the properties of the substrate and on an applied voltage. An analytical model is developed that describes the Fermi level shift as a function of the gate voltage, of the substrate work function, and of the type and thickness of the dielectric spacer. The parameters of this model, that should describe the effect of gate electrodes in field-effect devices, can be obtained from density functional theory (DFT) calculations on single layers or interfaces. The doping of graphene in metal|dielectric|graphene structures is found to be determined not only by the difference in work function between the metal and graphene and the dielectric properties of the spacer but potential steps that result from details of the microscopic bonding at the interfaces also play an important role. The doping levels predicted by the model agree very well with the results obtained from first-principles DFT calculations on metal|dielectric|graphene structures with the metals Al, Co, Ni, Cu, Pd, Ag, Pt or Au, and a h-BN or vacuum dielectric spacer.

References in corpus (13)

• Electric Field Effect in Atomically Thin Carbon Films
• Two Dimensional Atomic Crystals
• Ultrahigh electron mobility in suspended graphene
• Boron nitride substrates for high-quality graphene electronics
• Doping graphene with metal contacts
• Vertical Field Effect Transistor based on Graphene-WS2 Heterostructures for flexible and transparent electronics
• STM Spectroscopy of ultra-flat graphene on hexagonal boron nitride
• Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride
• Atomically thin boron nitride: a tunnelling barrier for graphene devices
• Giant Phonon-induced Conductance in Scanning Tunneling Spectroscopy of Gate-tunable Graphene
• Evidence of the role of contacts on the observed electron-hole asymmetry in graphene
• Work functions of self-assembled monolayers on metal surfaces
• Quantum behavior of graphene transistors near the scaling limit

Cited by in corpus (3)

• Theory of proximity-induced exchange coupling in graphene on hBN/(Co, Ni)
• Suppression of contact-induced spin dephasing in graphene/MgO/Co spin-valve devices by successive oxygen treatments
• Large potential steps at weakly interacting metal-insulator interfaces