Comparison of β-Ga2O3 thin films grown on r-plane and c-plane sapphire substrates

Abstract

Solar-blind UV detectors based on gallium oxide thin films have attracted extensive attention for potential civil and military applications. Substrate selection plays an important role for hetero-epitaxial growth of gallium oxide thin films. Herein, β-Ga2O3 thin films were deposited on r-plane and c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. The microstructure of the β-Ga2O3 thin films were analyzed by X-ray diffraction and transmission electron microscope. (2¯01)-oriented β-Ga2O3 thin films were grown on c-plane sapphire. While, β-Ga2O3 thin films with both (100) and (001) oriented grains were prepared on r-plane sapphire. Moreover, photodetectors were fabricated. Detectivity of the photodetectors made from β-Ga2O3 thin films on r-plane and c-plane sapphire is about 1.3 × 1014 Jones and 7.2 × 1013 Jones, respectively. The β-Ga2O3 thin films grown on r-plane sapphire is benefit for solar-blind UV detectors fabrication.