Structurally and Chemically Compatible BiInSe3 Substrate for Topological Insulator Thin Films

TL;DR

This paper introduces BiInSe3 as an ideal substrate for Bi2Se3 topological insulator films, improving film quality through better structural and chemical compatibility, which enhances surface morphology, reduces defects, and increases mobility.

Contribution

The study presents BiInSe3 as a novel, compatible substrate for Bi2Se3 films, enabling higher quality topological insulator films with superior properties compared to existing substrates.

Findings

BiInSe3 substrate improves film surface morphology

BiInSe3 reduces defect density in Bi2Se3 films

BiInSe3 enhances Hall mobility of the films

Abstract

Quality of epitaxial films strongly depends on their structural and chemical match with the substrates: the more closely they match, the better the film quality is. Topological insulators (TI) such as Bi2Se3 thin films are of no exception. However, there do not exist commercial substrates that match with TI films both structurally and chemically, at the level commonly available for other electronic materials. Here, we introduce BiInSe3 bulk crystal as the best substrate for Bi2Se3 thin films. These films exhibit superior surface morphology, lower defect density and higher Hall mobility than those on other substrates, due to structural and chemical match provided by the BiInSe3 substrate. BiInSe3 substrate could accelerate the advance of TI research and applications.