Growth studies and optical properties of Zn1−xCdxO films grown by metal-organic chemical-vapor deposition

Heteroepitaxial growths of Zn1−xCdxO films were performed on R-oriented sapphire substrates by metal-organic chemical-vapor deposition. The authors carried out secondary ion mass spectrometry analysis, scanning electron microscopy, photoluminescence, and ellipsometric measurements to investigate the incorporation of cadmium in the layers, as well as its influence on the optical properties. Compositions up to 5.5% Cd were obtained, tuning the photoluminescence emission from 3.36 (ZnO) to 3.1 eV and increasing the refractive index at 600 nm from 1.94 to 2.