Growth and Characterization of Molybdenum Disulfide Thin Films

Growth and Characterization of Molybdenum Disulfide Thin Films.Two-dimensional materials, or materials that are only one atomic layer thick, have seen much research in recent years because of their interesting electrical properties.The first of these materials, graphene, was found to have incredible electrical properties but lacked a bandgap in intrinsic films.Without a bandgap, graphene cannot create transistors that can be shut off.Molybdenum disulfide, however, is a two-dimensional semiconductor with a large bandgap.The main issue of molybdenum disulfide is that synthesized films are a much lower quality than their exfoliated counterparts.For molybdenum disulfide to be able to be used practically, a method of synthesis must be found that can reliably create quality large area monolayer films.In this thesis, three methods of molybdenum disulfide film synthesis are presented.Methods implemented used a tube furnace as a chemical vapor deposition system to evaporate source materials to synthesize thin films of molybdenum disulfide.An exploration into the different synthesis parameters shows optimal conditions for these specific methods.Then a discussion of these different methods is presented by judging films grown by using these methods on relevant criteria.This work shows methods to synthesize large area, polycrystalline, small grain, multilayer films, both intrinsic and doped, and to synthesize small area, single crystal and polycrystalline, monolayer films of molybdenum disulfide.