Impact of reduced graphene oxide on MoS{sub 2} grown by sulfurization of sputtered MoO{sub 3} and Mo precursor films

• Published in: Journal of vacuum science & technology. A, Vacuum, surfaces, and films Vacuum, surfaces, and films, 2016-07, Vol.34 (4)
• Main Authors: Pacley, Shanee, Brausch, Jacob, Beck-Millerton, Emory, Hu, Jianjun, Jespersen, Michael, Hilton, Al, Waite, Adam, Voevodin, Andrey A.
• Format: Article
• Language: English
• Subjects: ATOMIC FORCE MICROSCOPY; CHEMICAL VAPOR DEPOSITION; COMPARATIVE EVALUATIONS; EVAPORATION; FIELD EFFECT TRANSISTORS; GRAIN GROWTH; GRAIN SIZE; GRAPHENE; MATERIALS SCIENCE; MOLYBDENUM CHLORIDES; MOLYBDENUM OXIDES; MOLYBDENUM SULFIDES; POWDERS; PRECURSOR; SILICON OXIDES; SPUTTERING; SULFUR; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; VAPOR DEPOSITED COATINGS; X-RAY PHOTOELECTRON SPECTROSCOPY
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.4952399

Monolayer molybdenum disulfide (MoS{sub 2}), a two dimensional semiconducting dichalcogenide material with a bandgap of 1.8–1.9 eV, has demonstrated promise for future use in field effect transistors and optoelectronics. Various approaches have been used for MoS{sub 2} processing, the most common being chemical vapor deposition. During chemical vapor deposition, precursors such as Mo, MoO{sub 3}, and MoCl{sub 5} have been used to form a vapor reaction with sulfur, resulting in thin films of MoS{sub 2}. Currently, MoO{sub 3} ribbons and powder, and MoCl{sub 5} powder have been used. However, the use of ribbons and powder makes it difficult to grow large area-continuous films. Sputtering of Mo is an approach that has demonstrated continuous MoS{sub 2} film growth. In this paper, the authors compare the structural properties of MoS{sub 2} grown by sulfurization of pulse vapor deposited MoO{sub 3} and Mo precursor films. In addition, they have studied the effects that reduced graphene oxide (rGO) has on MoS{sub 2} structure. Reports show that rGO increases MoS{sub 2} grain growth during powder vaporization. Herein, the authors report a grain size increase for MoS{sub 2} when rGO was used during sulfurization of both sputtered Mo and MoO{sub 3} precursors. In addition, our transmission electron microscopy results show a more uniform and continuous film growth for the MoS{sub 2} films produced from Mo when compared to the films produced from MoO{sub 3}. Atomic force microscopy images further confirm this uniform and continuous film growth when Mo precursor was used. Finally, x-ray photoelectron spectroscopy results show that the MoS{sub 2} films produced using both precursors were stoichiometric and had about 7–8 layers in thickness, and that there was a slight improvement in stoichiometry when rGO was used.