THEORETICAL-STUDY OF THE ENERGY-BAND STRUCTURE OF PARTIALLY CUPT-ORDERED GA0.5IN0.5P

We propose a model for the partially ordered Ga0.5In0.5P alloys in whi ch the CuPt structure is always retained. A long-range order parameter is defined in terms of the cation potentials on the group-III sublatt ice. Using this model we studied the electronic band structure of Ga0. 5In0.5P alloys as a continuous function of the order parameter using t he empirical pseudopotential method. Trends in the fundamental energy gap and effective masses are obtained. We found that the anisotropy in the effective masses is enhanced by ordering.