Determination of the optical gap bowing parameter for ternary Ni1-xZnxO cubic rocksalt solid solutions.

The lattice parameter variation for phase pure cubic rocksalt (RS) Ni1-xZnxO ternary solid solutions is observed to be perfectly governed by Vegard's law. X-ray absorption near edge spectroscopy confirms the RS symmetry of Zn atoms in the cubic lattice of Ni1-xZnxO. The optical gap bowing parameter for RS Ni1-xZnxO ternary solid solutions is determined, using diffuse reflectivity, to be -0.93 ± 0.05 eV. The negative value of the bowing indicates a repulsive interaction between the ligand O-2p and the metal Ni-3d orbitals. The determined value of the bowing parameter can be useful in designing UV photodetectors based on Ni1-xZnxO solid solutions.