Molecular Beam Epitaxy of a 2D material nearly lattice matched to a 3D substrate: $NiTe_{2}$ on $GaAs$

TL;DR

This paper reports the first successful molecular beam epitaxy growth of NiTe₂, a 2D transition metal dichalcogenide, on a nearly lattice-matched GaAs substrate, enabling high-quality 2D/3D heterostructures.

Contribution

It demonstrates the epitaxial growth of NiTe₂ on GaAs using molecular beam epitaxy, a novel achievement for this 2D material on a 3D substrate.

Findings

NiTe₂ layers are metallic with high Hall carrier concentrations.

Structural analysis confirms high-quality epitaxial growth.

Surface and atomic-scale imaging show well-ordered layers.

Abstract

The lattice mismatch between interesting 2D materials and commonly available 3D substrates is one of the obstacles in the epitaxial growth of monolithic 2D/3D heterostructures, but a number of 2D materials have not yet been considered for epitaxy. Here we present the first molecular beam epitaxy growth of NiTe$_{2}$ 2D transition metal dichalcogenide. Importantly, the growth is realized on a nearly lattice matched GaAs(111)B substrate. Structural properties of the grown layers are investigated by electron diffraction, X-ray diffraction, and scanning tunnelling microscopy. Surface coverage and atomic scale order is evidenced by images obtained with atomic force, scanning electron, and transmission electron microscopy. Basic transport properties were measured confirming that NiTe$_{2}$ layers are metallic, with the Hall concentration of $10^{20}$cm$^{-3}$ to $10^{23}$cm$^{-3}$, depending on the growth conditions.