P-type doping in edge-enriched MoS2-x nanostructure via RF generated nitrogen plasma

Abstract

This work shows an intuitive magnetron sputtering technique to synthesize vertically aligned edge-enriched MoS2 (v-MS) nanostructures. The morphology and orientation of the as-synthesized nanostructure can be modified by altering the parameters of the sputtering process. This work emphasizes the versatility of magnetron sputtering to synthesize different orientated 2D nanostructures. These structures may have diverse applications, such as optoelectronics, hydrogen evolution, sensors, energy storage and catalysis. The vertically aligned nanostructure of MoS2 is confirmed using the field emission scanning electron microscopy and Raman spectroscopy techniques. Furthermore, we studied the plasma-based nitrogen doping process with minimal damage for introducing nitrogen atoms into 2D nanomaterials. A plasma produced in a nitrogen environment, assisted by a simple radio frequency (RF) power supply, is employed for p-type doping in v-MS. The successful doping of nitrogen has been investigated through the use of Raman spectroscopy and X-ray photoelectron spectroscopy. The atomic force microscope images confirm the little surface damage resulting from the nitrogen doping technique. The change of work function resulting from doping is examined by Kelvin Probe force microscopy and ultraviolet photoelectron spectroscopy. Optical emission spectroscopy (OES) study reveals the role of nitrogen plasma ions in doping with minimal surface damaging. This work demonstrates the effective intimidation of the work function of the MoS2 nanomaterial via plasma treatment.