Elastic modeling and total energy calculations of the structural characteristics of “free-standing,” periodic, pseudomorphic GaN/AlN superlattices

The strain states of the components of pseudomorphic superlattices can be accurately modeled analytically through the application of linear elasticity. In this particular case of GaN/AlN “free-standing” superlattices, the predictions derived from elastic modeling have been compared with total energy calculations of several systems made of components with varying thicknesses. We demonstrate that the elastic predictions for the lattice constants of the components align with the values obtained from their total energy counterparts, within the limits of computational errors and uncertainties. Furthermore, a phenomenological analysis of the elastic energy stored in the superlattices facilitates the evaluation of the excess energies associated with the interfaces present in these systems. The results mentioned above are briefly contrasted with findings reported in previous literature.