Electronic and optical properties of GaAsN/GaAs quantum wells: A tight-binding study

We present empirical tight-binding (TB) calculations of the electronic structure of GaAs1−xNx/GaAs (001) quantum wells (QWs) with small N concentrations (0band offset (VBO) between GaAs and GaAs1−xNx. The dependences of the bound states energies on the QW width and on the N concentration x are investigated and the nature of the lowest-energy optical transitions is analyzed, showing that the knowledge of the first two optical transitions is sufficient to determine the value of the VBO. Our results are compared with experimental data from the literature, revealing good agreement for x⩽0.02. For larger concentrations, we find that the agreement is greatly improved if the concentrations determined from x-ray diffraction data are corrected for deviations from Vegard’s rule. The comparison with exp...