Synthesis of High-Density Indium Oxide Nanowires with Low Electrical Resistivity

In this study, indium oxide nanowires of high-density were synthesized by chemical vapor deposition (CVD) through a vapor-liquid-solid (VLS) mechanism without carrier gas. The indium oxide nanowires possess great morphology with an aspect ratio of over 400 and an average diameter of 50 nm; the length of the nanowires could be over 30 μm, confirmed by field-emission scanning electron microscopy (SEM). Characterization was conducted with X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence spectrum (PL). High-resolution TEM studies confirm that the grown nanowires were single crystalline c-In₂O₃ nanowires of body-centered cubic structures. The room temperature PL spectrum shows a strong peak around 2.22 eV, originating from the defects in the crystal structure. The electrical resistivity of a single indium oxide nanowire was measured to be 1.0 × 10^-4 Ω⋅cm, relatively low as compared with previous works, which may result from the abundant oxygen vacancies in the nanowires, acting as unintentional doping.