Structural and electronic properties of highly doped topological insulator Bi2Se3 crystals

TL;DR

This study investigates the structural and electronic characteristics of highly doped Bi2Se3 topological insulator crystals, revealing high-quality structure, topological surface states, and bulk conduction dominance, with insights into reducing bulk conductance.

Contribution

It provides comprehensive structural and electronic analysis of highly doped Bi2Se3, including direct observation of topological surface states and bulk quantum Hall effect.

Findings

High-quality single crystals confirmed by X-ray, STM, and Raman.

Topological surface states observed via ARPES.

Bulk conduction dominates transport, with a bulk quantum Hall effect.

Abstract

We present a study of the structural and electronic properties of highly doped topological insulator Bi2Se3 single crystals synthesized by the Bridgman method. Lattice structural characterizations by X-ray diffraction, scanning tunneling microscopy, and Raman spectroscopy confirmed the high quality of the as-grown single crystals. The topological surface states in the electronic band structure were directly re- vealed by angle-resolved photoemission spectroscopy. Transport measurements showed that the conduction was dominated by the bulk carriers and confirmed a previously observed bulk quantum Hall effect in such highly doped Bi2Se3 samples. We briefly discuss several possible strategies of reducing bulk conductance.