Growth of quantum well films of topological insulator Bi2Se3 on insulating substrate

TL;DR

This paper reports the successful growth of high-quality Bi2Se3 quantum well films on sapphire substrates using molecular beam epitaxy, enabling better study of topological insulators' low-dimensional physics.

Contribution

It demonstrates the growth of uniform, high-quality Bi2Se3 quantum well films on insulating substrates, suitable for electrical transport studies.

Findings

Films exhibit well-defined quantum well and surface states

Uniform thickness over large areas

Negligible substrate conduction contribution

Abstract

Insulating substrates are crucial for electrical transport study and room temperature application of topological insulator films at thickness of only several nanometers. High quality quantum well films of Bi2Se3, a typical three-dimensional topological insulator, have been grown on \alpha-Al2O3 (sapphire) (0001) by molecular beam epitaxy. The films exhibit well-defined quantum well states and surface states, suggesting the uniform thickness over macroscopic area. The Bi2Se3 thin films on sapphire (0001) provide a good system to study low-dimensional physics of topological insulators since conduction contribution from the substrate is negligibly small.