Model for the formation energy of In-N clusters and their effect on the energy band gap of the Ga-rich and As-rich InxGa1−xNyAs1−y semiconductor alloys

A model for the formation energy of In-N clusters in InxGa1−xNyAs1−y alloys is developed. It is found that when the number of In atoms bonded to one N atom reaches 2.7, the lattice constant in the neighborhood of N atoms matches that of GaAs and the local strain decreases to the minimum. The relationship among the spectral blueshift, the formation energy of one In-N bond, the average number of nearest-neighbor In atoms per N atom, and the nitrogen level is also discussed. It is helpful to further investigate the relationship between the spectral blueshift and the annealing parameters.