Current Applied Physics, Vol.20, No.10, 1130-1135, 2020
Epitaxial growth of < 010 >-oriented MoO2 nanorods on m-sapphire
Molybdenum dioxide (MoO2) materials have attracted considerable interests due to their superduper properties and potential applications, relating to the growth directions and exposed surfaces. Here, we reported as the substrate changes from c-to m-sapphire, the growth direction of epitaxial MoO2 nanorods via an atmospheric pressure chemical vapor deposition approach changes along from <001> to <010> of bulk monoclinic MoO2 accompanied by exposing different surfaces. Optical microscopy (OM), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cross-sectional scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) measurements reveal these MoO2 nanorods are epitaxially grown on m-sapphire substrates with the orientation of MoO2 (101)//sapphire (10 (1) over bar0) and MoO2 <010> in line with sapphire <0001>. The electrical conductivity significantly depends on the crystallographic direction of MoO2 nanorods. The method to control the growth directions of 1D MoO2 nanorods has potential applications in nanoelectronic devices.