Quasi-freestanding and single-atom thick layer of hexagonal boron nitride as a substrate for graphene synthesis

TL;DR

This study demonstrates a method to produce a quasi-freestanding, single-atom thick hexagonal boron nitride layer as a substrate for graphene synthesis, revealing potential for advanced electronic applications.

Contribution

It introduces a novel intercalation technique to detach hBN from a metal substrate, enabling high-quality graphene growth on an insulating layer.

Findings

Au intercalation frees hBN from Ni(111) substrate

Graphene successfully synthesized on quasi-freestanding hBN

Transition to quasi-freestanding state alters hBN lattice constant

Abstract

We demonstrate that freeing a single-atom thick layer of hexagonal boron nitride (hbn) from tight chemical bonding to a Ni(111) thin film grown on a W(110) substrate can be achieved by intercalation of Au atoms into the interface. This process has been systematically investigated using angle-resolved photoemission spectroscopy, X-ray photoemission and absorption techniques. It has been demonstrated that the transition of the hbn layer from the "rigid" into the "quasi-freestanding" state is accompanied by a change of its lattice constant. Using chemical vapor deposition, graphene has been successfully synthesized on the insulating, quasi-freestanding hbn monolayer. We anticipate that the in situ synthesized weakly interacting graphene/hbn double layered system could be further developed for technological applications and may provide perspectives for further inquiry into the unusual electronic properties of graphene.