Pulsed laser deposition of high-quality ZnCdO epilayers and ZnCdO/ZnO single quantum well on sapphire substrate

Abstract

The authors report on high quality ZnCdO alloy epilayers and ZnCdO/ZnO single quantum well structures on sapphire substrates by pulsed laser deposition. The Cd concentration in the ZnCdO alloy can be systematically adjusted via the substrate temperature and single-phase ZnCdO alloy with a band gap at room temperature extended to 2.94 eV is achieved. The single quantum well structures exhibit strong photoluminescence from the well layer with extremely weak emission from deep level defects and the ZnO barrier, indicating the high quality of ZnCdO/ZnO single quantum well structures.