Precisely aligned graphene grown on hexagonal boron nitride by catalyst free chemical vapor deposition

TL;DR

This study demonstrates the growth of precisely aligned graphene on hexagonal boron nitride via catalyst-free chemical vapor deposition, revealing high-quality heterostructures with potential for advanced electronic applications.

Contribution

It introduces a method for catalyst-free growth of aligned graphene on h-BN with atomic precision, confirmed by moiré patterns and low alignment error.

Findings

Graphene aligns within 0.05 degrees of h-BN lattice.

Moiré patterns indicate van der Waals epitaxy and stress release.

Field effect mobility exceeds 20,000 cm²/V·s at room temperature.

Abstract

To grow precisely aligned graphene on h-BN without metal catalyst is extremely important, which allows for intriguing physical properties and devices of graphene/h-BN hetero-structure to be studied in a controllable manner. In this report, such hetero-structures were fabricated and investigated by atomic resolution scanning probe microscopy. Moirre patterns are observed and the sensitivity of moirre interferometry proves that the graphene grains can align precisely with the underlying h-BN lattice within an error of less than 0.05 degree. The occurrence of moirre pattern clearly indicates that the graphene locks into h-BN via van der Waals epitaxy with its interfacial stress greatly released. It is worthy to note that the edges of the graphene grains are primarily oriented along the armchair direction. The field effect mobility in such graphene flakes exceeds 20,000 cm2/V.s at ambient condition. This work opens the door of atomic engineering of graphene on h-BN, and sheds light on fundamental research as well as electronic applications based on graphene/h-BN hetero-structure.