Lateral Heterojunction Sb2Te3/Bi2Te3 and its topological transport

TL;DR

This paper reports the synthesis and characterization of a lateral heterojunction between topological insulators Sb2Te3 and Bi2Te3, revealing topological surface state transport and potential for spintronic applications.

Contribution

The study demonstrates a successful two-step solvothermal synthesis of a well-defined lateral heterojunction with epitaxial growth and topological surface state transport properties.

Findings

Sharp lattice-matched interface confirmed by TEM

Observation of rectification at low temperatures

Quantum correction indicates topological surface state transport

Abstract

A lateral heterojunction of topological insulator Sb2Te3/Bi2Te3 was successfully synthesized using a two-step solvothermal method. The two crystalline components were separated well by a sharp lattice-matched interface when the optimized procedure was used. Inspecting the heterojunction using high-resolution transmission electron microscopy showed that epitaxial growth occurred along the horizontal plane. A rectification curve was observed at low temperatures. Quantum correction from the weak antilocalization reveals the transport of the topological surface state. There was, therefore, a staggered-gap lateral heterojunction with a small junction voltage, which is appealing for a platform for spin filters and one-dimensional topological interface states.