One-Dimensional Electrical Contact to a Two-Dimensional Material

TLDR

Heterostructures of 2D materials such as graphene and hexagonal boron nitride promise new electronic devices, but high‑quality electrical contacts are essential. The study reports a contact geometry that metalizes only the 1D edge of a 2D graphene layer. This edge‑contact geometry outperforms conventional surface contacts and separates layer assembly from contact metallization. The edge‑contact enables high electronic performance, including low‑temperature ballistic transport over longer than 15 µm and room‑temperature mobility near the phonon‑scattering limit, and offers new design possibilities for multilayered 2D structures.

Abstract

Heterostructures based on layering of two-dimensional (2D) materials such as graphene and hexagonal boron nitride represent a new class of electronic devices. Realizing this potential, however, depends critically on the ability to make high-quality electrical contact. Here, we report a contact geometry in which we metalize only the 1D edge of a 2D graphene layer. In addition to outperforming conventional surface contacts, the edge-contact geometry allows a complete separation of the layer assembly and contact metallization processes. In graphene heterostructures, this enables high electronic performance, including low-temperature ballistic transport over distances longer than 15 micrometers, and room-temperature mobility comparable to the theoretical phonon-scattering limit. The edge-contact geometry provides new design possibilities for multilayered structures of complimentary 2D materials.