Topological insulator Bi2Te3 films synthesized by metal organic chemical vapor deposition

TL;DR

This paper reports the successful synthesis of high-quality Bi2Te3 topological insulator thin films using a scalable MOCVD method, with detailed characterization confirming their topological surface states and promising electronic properties for applications.

Contribution

First demonstration of high-quality Bi2Te3 TI films grown by MOCVD with comprehensive structural and electronic characterization.

Findings

Topological surface states with a single Dirac cone confirmed by ARPES.

High bulk carrier mobility up to 7,400 cm^2/Vs at 15 K.

Films exhibit promising thermoelectric properties.

Abstract

Topological insulator (TI) materials such as Bi2Te3 and Bi2Se3 have attracted strong recent interests. Large scale, high quality TI thin films are important for developing TI-based device applications. In this work, structural and electronic properties of Bi2Te3 thin films deposited by metal organic chemical vapor deposition (MOCVD) on GaAs (001) substrates were characterized via X-ray diffraction (XRD), Raman spectroscopy, angle-resolved photoemission spectroscopy (ARPES), and electronic transport measurements. The characteristic topological surface states (SS) with a single Dirac cone have been clearly revealed in the electronic band structure measured by ARPES, confirming the TI nature of the MOCVD Bi2Te3 films. Resistivity and Hall effect measurements have demonstrated relatively high bulk carrier mobility of ~350 cm^2/Vs at 300K and ~7,400 cm^2/Vs at 15 K. We have also measured the Seebeck coefficient of the films. Our demonstration of high quality topological insulator films grown by a simple and scalable method is of interests for both fundamental research and practical applications of thermoelectric and TI materials.