Band gap bowing in NixMg1−xO

• DOI: 10.1038/srep31230
• Publication Date: 2016-08-09T09:09:39Z
• Authors: Christian A. Nied...; Mikael Råsander; Sneha Rhode; Vyacheslav Kachkanov; Bin Zou; Neil Alford; Michelle A. Moram
• Keywords: Bowing; Pulsed Laser Deposition

Epitaxial transparent oxide NixMg1-xO (0 ≤ x 1) thin films were grown on MgO(100) substrates by pulsed laser deposition. High-resolution synchrotron X-ray diffraction and high-resolution transmission electron microscopy analysis indicate that the are compositionally structurally homogeneous, forming a completely miscible solid solution. Nevertheless, composition dependence of optical band gap shows strong non-parabolic bowing with discontinuity at dilute NiO concentrations < 0.037. Density functional calculations structure density states demonstrate deep Ni 3d levels introduced into MgO gap, which significantly reduce fundamental as confirmed absorption spectra. These broaden 3d-derived conduction for > 0.074 account anomalously large narrowing in solution system.