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Access Type
WSU Access
Date of Award
January 2023
Degree Type
Thesis
Degree Name
M.S.
Department
Electrical and Computer Engineering
First Advisor
Ivan Avrutsky
Abstract
In the frontier of advanced materials research, the focus is on development of transition metal dichalcogenides (TMDs), specifically monolayer molybdenum disulfide (MoS2), which could play a pivotal role in semiconductor and optoelectronic devices. The innovative aspect of 2D material research lies in the incorporation of growth promoters in the Chemical Vapor Deposition (CVD) process, to tailor materials for various applications. In this regard utilization of halide assist is instrumental in lowering the required temperatures for the growth of MoS2, thereby enhancing the efficiency of the process. 2D-MoS2 is synthesized by using sodium-based precursors that condense on the substrate, effectively reducing the energy requirements of the reaction. The NaCl-MoS2 through CVD synthesis marks an improvement in the quality of MoS2 layers produced on multiple substrates, including amorphous, crystalline, and layered types. Significantly, the study highlights the effectiveness of MoS2 large flake growth on SiO2/Si at lower synthesis temperatures. The presence of halide species in the CVD growth reaction which influences the nucleation process, through the formation of nucleation sites across the substrate surface. In the process of NaCl-MoS2 growth, secondary seeding layer formation which composed of Na2S and Na2SO4. This layer not only facilitates the 2D planar nucleation of MoS2 but also streamlines the transfer process, thanks to the solubility of these compounds. This development paves the way for the large-scale synthesis of high-quality MoS2, on a wide range of substrates, including temperature sensitive materials (glass, flexible substrate(polyimide/PET) etc.,) which were previously not suitable for high-temperature CVD process.
Recommended Citation
Gottumukkala, Sundeep Varma, "2d-Mos2 Cvd Growth Optimization: Synthesis, Characterizations And Applications In Photodetectors" (2023). Wayne State University Theses. 932.
https://digitalcommons.wayne.edu/oa_theses/932