The electronic structure of Ge-Se and Ge-Te compounds

The author presents for the first time the results of electronic structure calculations carried out on GeSe and GeTe compounds using a modification of the chemical pseudopotential method. Calculated densities of states for crystalline GeSe and GeTe are in excellent agreement with experiment. The backbond environment is found to play a major role in determining the structure of the p-bonding band, whereas the s bands are determined predominantly by nearest-neighbour interactions. The density of states of the Matthews-Davis-Elliott even-membered ring network is also calculated and the relevance of this model to studies of amorphous As, GeSe and GeTe is discussed.