Dependence of the band structure on the order parameter for partially ordered GaxIn1-xP alloys - art. no. 201312

An empirical pseudopotential method is demonstrated for realistically and a ccurately calculating the band structure of partially CuPt ordered GaxIn1-x P alloys. A sufficiently large supercell of similar to 3500 atoms, with all atomic positions relaxed by applying a valence force field method, is used to simulate the (Ga,In) distribution in the partially ordered alloy with t he order parameter eta varying from 0 to 1. While agreeing very well with e xperimental data in the experimentally verifiable region eta <0.5, our resu lts illustrate that a commonly accepted interpolation scheme (i.e., the <et a>(2) rule) is grossly inaccurate for determining certain primary band stru cture parameters (e.g., the band gap) between eta =0 and eta =1.