BAND-STRUCTURE OF BETE - A COMBINED EXPERIMENTAL AND THEORETICAL-STUDY

Using angle-resolved synchrotron-radiation photoemission spectroscopy we have determined the dispersion of the valence bands of BeTe(100) al ong Gamma X, i.e., the [100] direction. The measurements are analyzed with the aid of a first-principles calculation of the BeTe bulk band s tructure as well as of the photoemission peaks as given by the momentu m-conserving bulk transitions. Taking the calculated unoccupied bands as final states of the photoemission process, we obtain an excellent a greement between experimental and calculated spectra and a clear inter pretation of almost all measured bands. In contrast, the free-electron approximation for the final states fails to describe the BeTe bulk ba nd structure along Gamma X properly. [S0163-1829(98)02739-8].