Optical Characteristics of ZnTeO Thin Films Synthesized by Pulsed Laser Deposition and Molecular Beam Epitaxy

Oxygen incorporation into ZnTe was studied using pulsed laser deposition and molecular beam epitaxy. Oxygen incorporation at the high partial pressures studied for pulsed laser deposition was found to result in increasing visible transparency with oxygen incorporation, and is attributed to the formation of TeOx based on bonding information obtained by x-ray photoelectron spectroscopy measurements. Oxygen incorporation by a plasma source during the growth of ZnTe by molecular beam epitaxy was found to result in an electronic band at 0.5 eV below the ZnTe band edge, possessing strong radiative properties and a resonant-like optical absorption coefficient with a peak α > 5000 cm−1. The ZnTeO thin films grown by MBE have an epitaxial structure similar to ZnTe, where it is unclear whether the properties are due to the formation of a high-density defect level or the formation of a dilute alloy.