Catalyst free single-step processes to grow crystalline MoO3 nanowires by reactive sputtering method

Abstract

In this paper for the first time, we report a single-step catalyst free method to grow crystalline molybdenum oxide nanowires over a large area using a reactive DC sputtering technique. We demonstrate that the shape and size of the nanostructures can be tuned by choosing the appropriate temperature and sputtering power as controlled parameters. A pin-like nanowire structure was observed at 400 °C, which subsequently was converted to nanowires (NWs) at 500 °C. An increase in the temperature to 600 °C converted the NWs to a rough film. In addition, the length of the nanowires was increased by performing the deposition for a longer time. Furthermore, the effect of the sputtering power on the transformation of the shape and size of the nanostructures was shown. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) confirmed the high crystalline nature of the well grown NWs. The present study will be useful to grow various shaped and sized MoO3 nanostructures over a large area for future optoelectronic applications including solar cells and photodetectors.