Tuning transport across MoS2/graphene interfaces via as-grown lateral heterostructures

Abstract

An unexploited property of graphene-based heterojunctions is the tunable doping of the junction via electrostatic gating. This unique property may be key in advancing electronic transport across interfaces with semiconductors. Here, we engineer transport in semiconducting TMDs by constructing a lateral heterostructure with epitaxial graphene and tuning its intrinsic doping to form a p–n junction between the graphene and the semiconducting TMDs. Graphene grown on SiC (epitaxial graphene) is intrinsically doped via substrate polarization without the introduction of an external dopant, thus enabling a platform for pristine heterostructures with a target band alignment. We demonstrate an electrostatically tunable graphene/MoS2p–n junction with >20× reduction and >10× increased tunability in contact resistance (Rc) compared with metal/TMD junctions, attributed to band alignment engineering and the tunable density of states in graphene. This unique concept provides improved control over transport across 2D p–n junctions.

Spin-dependent vibronic response of a carbon radical ion in two-dimensional WS2

“…This neutral charge is a consequence of the different band alignments of WS 2 and WSe 2 with the Gr/SiC substrate. In the WSe 2 /Gr/SiC heterostructure, the Fermi level lies roughly in the center of the WSe 2 bandgap, whereas it is 443 meV higher for WS 2 29 . Accordingly, the underlying substrate does not donate an electron to the dangling bond-like defect state of C Se in WSe 2 and thus remains empty.…”

Light–Matter Interaction in Quantum Confined 2D Polar Metals

“…These properties together with the possibility of their quantum mechanical tuning makes 2D polar metals in half van der Waals structures highly attractive for next generation plasmonics, quantum‐plamonics, and nano‐plasmonic materials. These half van der Waals materials are fully integrable with other promising optically active 2D materials such as transition metal dichalcogenides [ 70 ] and their heterostructures, [ 71–74 ] atomistic quantum emitters in 2D materials, [ 75 ] and topologically non‐trivial materials. Coupling with different material systems and (quasi‐) particles therein, might result not only in field enhancement but in new quasiparticles such as chiral plasmons [ 76 ] and plexcitons.…”

Vibronic response of a spin-1/2 state from a carbon impurity in two-dimensional WS2

“…This neutral charge is a consequence of the different band alignments of WS 2 and WSe 2 with the Gr/SiC substrate. In the WSe 2 /Gr/SiC heterostructure, the Fermi level lies roughly in the center of the WSe 2 band gap, whereas it is 443 meV higher for WS 2 [39].…”

“…This neutral charge is a consequence of the different band alignments of WS 2 and WSe 2 with the Gr/SiC substrate. In the WSe 2 /Gr/SiC heterostructure, the Fermi level lies roughly in the center of the WSe 2 band gap, whereas it is 443 meV higher for WS 2 [39]. Accordingly, the underlying substrate does not donate an electron to the dangling bond-like defect state of C Se in WSe 2 and thus remains empty.…”