Shape-controlled growth of beta-gallium oxide nanowires and experimental investigation on the origination of electrons.

Diameter-controlled growth of monoclinic gallium oxide nanowires was performed by chemical vapor deposition technique. Prior to growth, a thin layer of Au films was fabricated, SEM images indicated that Au could converge nanoparticles to govern the growth of β-Ga 2 O 3 nanowires. The SEM images revealed both diameter and length of β-Ga 2 O 3 nanowires strongly depended on the growth temperature. Nanowires grown at 1100 °C temperature have the minimum diameters and uniform lengths, compared with those grown at 900 °C and 1000 °C. The reasons are that a combination and a competition of vapor-liquid-solid (VLS) and vapor-solid (VS) mechanism occur in the growth process. High temperature would provide enough energy to make Ga and O atoms grow along one-dimensional axial orientation following the VLS mechanism. However, low temperature confines atoms at the nanowires interface and enhance sidewalls coalescence following the VS mechanism. X-ray diffraction (XRD) patterns and refinement indicated that the grown samples were of high crystallinity and had intrinsic oxygen vacancies. Photoluminescence spectra were examined and then followed by Gaussian fitting. Through analysis, the emission peaks were considered to originate from intrinsic oxygen vacancies and Ga-O vacancy pairs, consisting with the XRD refinement results. β-Ga 2 O 3 nanowires was coated on the interdigitated electrode, the response to the ultraviolet light and oxygen was studied. [ABSTRACT FROM AUTHOR]