MBE grown preferentially oriented CdMgO alloy on m- and c-plane sapphire substrates

Unlike other II-VI semiconductors, CdO-based transparent oxide has great potential application for the fabrication of many optoelectronic devices. In this work, we study the growth of CdxMg1-xO alloys on m-and on c-plane sapphire substrates in Cd-rich to Mg-rich conditions using the plasma-assisted molecular beam epitaxy method. A structural and morphological study of CdMgO random alloys was carried out using X-ray diffraction and Atomic Force Microscope (AFM) techniques whereas composition analysis was done by Energy-dispersive X-ray (EDX) spectroscopy method. The optical properties of thin films were investigated by UV-Vis spectroscopy at room temperature. X-ray analysis confirmed the presence of cubic rock salt structure with < 111 > CdMgO crystallographic orientation on c-plane sapphire and < 110 > CdMgO preferential orientation on m-plane sap-phire. The surface roughness was measured by the AFM. From the absorption curve, the optical bandgaps were determined using Tauc relation and it was found that the bandgap of films is influenced by the incorporation of Mg2+ ions into the CdO lattice. Bowing parameter was calculated for both samples on m- and c-sapphires.

Automated summary

In this study, the growth of CdO alloy using plasma-assisted molecular beam epitaxy method was investigated. The CdO alloy showed great potential for optoelectronic device fabrication. Structural and morphological analysis were conducted using X-ray diffraction and Atomic Force Microscopy techniques, while composition analysis was done by Energy-dispersive X-ray spectroscopy. The optical properties of thin films were studied using UV-Vis spectroscopy, and it was found that the bandgap of the films is affected by the incorporation of Mg2+ ions.