Atomic and electronic structures of InxGa1−xN quantum dots

We have calculated the atomic and electronic structures of the InxGa1−xN random alloys (0≤x≤1) based on 950 atom clusters. A valence-force-field method with a Keating-type potential is used for the strain energy calculation and, therefore, the equilibrium geometries. We analyzed the bond-length and bond-angle distribution in the alloy due to the random fluctuations of the atom positions. The change in the average Ga–N and In–N lengths is calculated as a function of the composition x and compared to recent experimental data. Once we have the equilibrium geometries we calculate the electronic structures of the alloys by means of the semi-empirical quantum method Extended Hueckel.