Molecular Beam Epitaxial Growth of Bi2Te3 and Sb2Te3 Topological Insulators on GaAs (111) Substrates: A Potential Route to Fabricate Topological Insulator p-n Junction

TL;DR

This study demonstrates the epitaxial growth of high-quality Bi2Te3 and Sb2Te3 topological insulator films on GaAs (111) substrates, highlighting their potential for fabricating topological insulator p-n junctions compatible with existing semiconductor devices.

Contribution

It introduces a method to grow topological insulator films on GaAs (111) substrates, enabling integration with current semiconductor technology.

Findings

Non-vicinal GaAs (111) substrates yield higher quality films.

p-type Sb2Te3 and n-type Bi2Te3 can be directly grown on GaAs (111).

Potential for fabricating topological insulator p-n junctions on GaAs.

Abstract

High quality Bi2Te3 and Sb2Te3 topological insulators films were epitaxially grown on GaAs (111) substrate using solid source molecular beam epitaxy. Their growth and behavior on both vicinal and non-vicinal GaAs (111) substrates were investigated by reflection high-energy electron diffraction, atomic force microscopy, x-ray diffraction, and high resolution transmission electron microscopy. It is found that non-vicinal GaAs (111) substrate is better than a vicinal substrate to provide high quality Bi2Te3 and Sb2Te3 films. Hall and magnetoresistance measurements indicate that p type Sb2Te3 and n type Bi2Te3 topological insulator films can be directly grown on a GaAs (111) substrate, which may pave a way to fabricate topological insulator p-n junction on the same substrate, compatible with the fabrication process of present semiconductor optoelectronic devices.