Improved photoluminescence performance of MgZnO films by alloying beryllium

We investigate the photoluminescence properties of MgZnO and BeMgZnO thin films that have been grown on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. Alloying MgZnO with Be results in the suppression of defect-related visible emission confirmed by the photoluminescence measurements and the decrease of background electron concentration of MgZnO confirmed by Hall measurements. Calculated formation energy of VO defects based on density functional theory (DFT) reveals that Be incorporation can suppress the formation of VO defects and results in the improvement of optical and electrical properties in MgZnO alloy. The Be source temperature plays an important role in determining the surface morphology, electrical and optical properties of BeMgZnO film. An optimized alloy is achieved at the Be source temperature 880 °C. The present work is of interest for developing a method to improve PL performance of MgZnO films.