Band structure of BeTe: A combined experimental and theoretical study

Abstract

Using angle-resolved synchrotron-radiation photoemission spectroscopy we have determined the dispersion of the valence bands of BeTe(100) along ΓX, 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 ΓX properly.

Band Discontinuity and Band Gap of MBE Grown HgTe/CdTe(001) Heterointerfaces Studied by k-Resolved Photoemission and Inverse Photoemission

“…Spectrum a was measured with a photon energy of 21.22 eV in normal emission (k k 0). Based on an estimate for the inner potential, V 0 10 AE 1 eV, which is in accordance with the values known for the (001) surfaces of II±VI semiconductors [17], the corresponding k c value is located at about 70% of the distance between the G-and the X-point. Spectrum b was also measured with He I but with an emission angle of 42…”

Electronic structure of BeTe and ZnTe

“…Our results are in close agreement with the measurements compared to others. Interestingly, state-of-the-art GW calculations [11] also underestimate (2.6 eV) the bandgap for BeTe. It is worth noticing that our results clearly identify the difference in the X 3 c and X 1 c , the latter being higher by 0.44 eV.…”

“…To our knowledge no such study is reported for BeTe or any other beryllium chalcogenide. The difficulty in growing single crystals along the principal crystallographic directions and the toxic nature could be the reason for the low number of experimental studies on these compounds [3,10,11]. However, the experimental Compton profile of ZnTe was reported [17] earlier using a 5Ci Am 241 source and was compared with the simple ionic model in the absence of any theoretical calculation.…”

“…Consequently, ab-initio methods are also applied to study these materials [8,[10][11][12][13]. X-ray form factors and dielectric constants have been studied by the self-consistent orthogonalized plane wave method [8].…”

“…The pseudopotential method has been applied to report elastic properties within the local density approximation [10]. The band dispersions along [100] are unraveled by applying a number of exchange correlation functions to compare with the angle-resolved photoemission spectroscopy [11]. Structural, electronic and dynamical properties have also been explored by employing the plane wave pseudopotential method considering the Perdew-Zunger and other exchange and correlation functions [12,13].…”