Date of Award
Master of Science in Materials Science and Engineering - (M.S.)
Committee for the Interdisciplinary Program in Materials Science and Engineering
N. M. Ravindra
Two dimensional materials such as graphene, boron nitride and transition metal dichalcogenide (TMDCs) monolayers have arisen as a new class of materials with unique properties at monolayer thickness. Their electrical, electronic and optical properties are of great importance for a variety of applications in optoelectronics as light emitters, detectors, and photovoltaic devices. This work focuses on MoS2 and WS2, which are two important members of the TMDC class of materials. The properties of monolayer MoS2 and WS2 are investigated as well as the properties of bulk MoS2 and WS2 to provide an understanding of their significant difference.
A detailed investigation of the electrical and electronic properties including temperature dependent resistivity, contact resistance, band structure and electronic excitation are discussed in this work. The temperature dependence of the energy gap for monolayer MoS2 and WS2 is also investigated. The optical properties of MoS2 and WS2, in the range of 1.5-3.0 eV, are modeled utilizing MATLAB simulations. Simulations of the optical properties of these materials on silicon, gold and fused silica substrates are presented. The optical band gap is simulated in order to compare with the electrical band gap. The future applications of both the materials are discussed.
Tang, Weitao, "Electrical, electronic and optical properties of MoS2 & WS2" (2017). Theses. 12.