Orbital contributions in the element-resolved valence electronic structure of Bi2Se3

TL;DR

This study uses standing wave-excited hard x-ray photoemission spectroscopy to analyze the element-specific orbital contributions in the valence band of the topological insulator Bi2Se3, providing detailed insights into its electronic structure.

Contribution

It introduces a novel application of SW-HAXPES to determine element-resolved orbital contributions in Bi2Se3, validated by DFT calculations.

Findings

Bi 6s, Bi 6p, and Se 4p states dominate the valence band.

SW-HAXPES effectively distinguishes element-specific orbital contributions.

Results align with density functional theory predictions.

Abstract

In this work, we studied the bulk band structure of a topological insulator (TI) Bi2Se3 and determined the contributions of the Bi and Se orbital states to the valence bands using standing wave-excited hard x-ray photoemission spectroscopy (SW-HAXPES). This SW technique can provide the element-resolved information and extract individual Bi and Se contributions to the Bi2Se3 valence band. Comparisons with density functional theory (DFT) calculations (LDA and GW) reveal that the Bi 6s, Bi 6p, and Se 4p states are dominant in the Bi2Se3 HAXPES valence band. These findings pave a way for studying the element-resolved band structure and orbital contributions of this class of TIs.