Molybdenum Disulfide Chemical Vapor Deposition Growth and Raman Characterization

Author(s):

Mitchell Hung, Kai Palam, Madan Dubey, and Charles Rong

Abstract:

Molybdenum disulfide (MoS₂) is a transition metal dichalcogenide (TMD) that has garnered attention as a potential alternative to silicon-based electronics. MoS₂ exhibits a direct band gap and is atomically flat and thin, making it ideal for use in transistors and optoelectronics. The ability for MoS₂ to be grown in monolayers due to its layered structure—molybdenum sandwiched by sulfur—gives the material a distinct advantage in precise growth. However, the growth of monolayer MoS₂ depends on a range of growth factors, including the choice and volume of growth promoters. We analyzed the effects of varying volumes of potassium bromide (KBr), the chosen growth promoter, on the shapes and properties of MoS₂ triangles. Using Raman spectroscopy, we observed that different KBr volumes led to changes in the spectral signatures and the formation of MoS₂ structures. Furthermore, we found via Raman peak and waveform analysis that lower volumes of KBr resulted in more consistent, repeatable results. This research supports the development of an automatic classification system for MoS₂ layers.