The band structure of BeTe - a combined experimental and theoretical study

TL;DR

This study combines experimental photoemission spectroscopy and first-principles calculations to accurately determine and interpret the valence band structure of BeTe(100), highlighting the importance of using calculated unoccupied bands for analysis.

Contribution

The paper presents a combined experimental and theoretical approach to accurately map the BeTe(100) valence band dispersion along $ ext{ΓX}$, demonstrating the effectiveness of using calculated unoccupied bands as final states.

Findings

Excellent agreement between experimental and calculated spectra.

Free electron approximation fails to describe BeTe band structure.

First-principles calculations effectively interpret photoemission data.

Abstract

Using angle-resolved synchrotron-radiation photoemission spectroscopy we have determined the dispersion of the valence bands of BeTe(100) along $\Gamma X$, i.e. the [100] direction. The measurements are analyzed with the aid of a first-principles calculation of the BeTe bulk band structure as well as of the photoemission peaks as given by the momentum conserving bulk transitions. Taking the calculated unoccupied bands as final states of the photoemission process, we obtain an excellent agreement between experimental and calculated spectra and a clear interpretation of almost all measured bands. In contrast, the free electron approximation for the final states fails to describe the BeTe bulk band structure along $\Gamma X$ properly.