Nonlocal Electrostatic Origin of Schottky-Barrier Variability in 2D Contacts

Hangbo Zhou; Yong-Wei Zhang

Nonlocal Electrostatic Origin of Schottky-Barrier Variability in 2D Contacts

Materials Science 2026-07-09 v1

Authors: Hangbo Zhou , Yong-Wei Zhang

Abstract

Electrical contacts often limit the performance of atomically thin semiconductor devices. The Schottky barrier height (SBH) is conventionally treated as a local interface property, yet reported values for the same metal/2D-semiconductor contact vary by hundreds of meV. Here we show that, in top contacts, the effective SBH exhibits a pronounced nonlocal electrostatic dependence on defects near the contact edge, beyond the conventional local interface framework. A nonlocal electrostatic model, supported by density-functional-theory-based transport calculations for Ti--MoS $_2$ and Au--MoS $_2$ , captures the large, metal-dependent variations in SBH as a function of defect position relative to the contact edge. These results provide a unified explanation for the longstanding variability in experimentally extracted SBHs and establish nonlocal electrostatics, mediated by edge-proximal defects, as a key mechanism governing carrier injection in 2D contacts.

Keywords

Schottky barrier height 2D contacts nonlocal electrostatics defects density functional theory carrier injection

Cite

@article{arxiv.2607.08253,
  title  = {Nonlocal Electrostatic Origin of Schottky-Barrier Variability in 2D Contacts},
  author = {Hangbo Zhou and Yong-Wei Zhang},
  journal= {arXiv preprint arXiv:2607.08253},
  year   = {2026}
}