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

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, beta-Ga2O3 thin films were deposited on r-plane and c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. The microstructure of the beta-Ga2O3 thin films were analyzed by X-ray diffraction and transmission electron microscope. ((2) over bar 01)-oriented beta-Ga2O3 thin films were grown on c-plane sapphire. While, beta-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 beta-Ga2O3 thin films on r-plane and c-plane sapphire is about 1.3 x 10(14) Jones and 7.2 x 10(13) Jones, respectively. The beta-Ga2O3 thin films grown on r-plane sapphire is benefit for solar-blind UV detectors fabrication.