Conductance asymmetry of graphene pn junction

Abstract

We use the non-equilibrium Green function (NEGF) method in the ballistic limit to provide a quantitative description of the conductance of graphene pn junctions - an important building block for graphene electronics devices. In this paper, recent experiments on graphene junctions are explained by a ballistic transport model, but only if the finite junction transition width, Dw, is accounted for. In particular, the experimentally observed anamolous increase in the resistance asymmetry between nn and np junctions under low source/drain charge density conditions is also quantitatively captured by our model. In light of the requirement for sharp junctions in applications such as electron focusing, we also examine the pn junction conductance in the regime where Dw is small and find that wavefunction mismatch (so-called pseudo-spin) plays a major role in sharp pn junctions.

7 pages, 6 figures

References in corpus (15)

• Electric Field Effect in Atomically Thin Carbon Films
• Chiral tunneling and the Klein paradox in graphene
• Suspended Graphene: a bridge to the Dirac point
• Electronic States of Graphene Nanoribbons
• Carrier transport in 2D graphene layers
• Veselago Lens for Electrons: Focusing and Caustics in Graphene p-n Junctions
• Selective transmission of Dirac electrons and ballistic magnetoresistance of \textit{n-p} junctions in graphene
• Transport measurements across a tunable potential barrier in graphene
• Electronic transport and quantum Hall effect in bipolar graphene p-n-p junction
• Weak antilocalization in epitaxial graphene: evidence for chiral electrons
• Conductance of p-n-p graphene structures with 'air-bridge' top gates
• Nonlinear screening and ballistic transport in a graphene p-n junction
• Modeling edge effects in Graphene Nanoribbon Field-effect Transistors with real and mode space methods
• Effective contact model for transport through weakly-doped graphene
• Towards Multi-Scale Modeling of Carbon Nanotube Transistors

Cited by in corpus (11)

• Gate-controlled Guiding of Electrons in Graphene
• Negative differential resistances with back gate-controlled lowest operation windows in graphene double barrier resonant tunneling diodes
• Ultra-sharp lateral $p\text{-}n$ junctions in modulation-doped graphene
• Contact-induced negative differential resistance in short-channel graphene FETs
• Efficient quantum transport simulation for bulk graphene heterojunctions
• Theory of Landau level mixing in heavily graded graphene p-n junctions
• Unipolar transport in bilayer graphene controlled by multiple p-n interfaces
• Reversible doping of graphene field effect transistors by molecular hydrogen: the role of the metal/graphene interface
• Effects of discrete topology on quantum transport across a graphene $n-p-n$ junction: A quantum gravity analogue
• Gate Tunable Lateral 2D pn Junctions: An Analytical Study of Its Electrostatics
• Valley focusing effect in a rippled graphene superlattice