Electronic properties of bismuth nanostructures

TL;DR

This paper investigates how passivation affects the electronic properties of bismuth nanostructures, combining first-principles calculations with many-body corrections to understand their semimetal-to-semiconductor transition.

Contribution

It provides a detailed first-principles analysis of passivation effects on bismuth films, including many-body interactions and transport properties, advancing understanding of their electronic behavior.

Findings

Passivation alters band structure and density of states.

Confinement effects influence the semimetal-to-semiconductor transition.

Calculated conductivity aligns with experimental two-channel model.

Abstract

The passivation of thin Bi(1 1 1) films with hydrogen and oxide capping layers is investigated from first principles. Considering termination-related changes of the crystal structure, we show how the bands and density of states are affected. In the context of the much discussed semimetal-to-semiconductor transition and the band topology of the bulk material, we consider the effects of confinement in the whole Brillouin zone and go beyond standard density functional theory by including many-body interactions via the G$_0$W$_0$ approximation. The conductivity of unterminated films is calculated via the Boltzmann transport equation using the simple constant relaxation time approximation and compared to experimental observations that have suggested a two-channel model.