Executive Summary : | The study focuses on the synthesis of large-area transition metal dichalcogenides (TMDCs) with configuration MX2, where M=Mo, or W and X= Se or S. TMDCs are being considered due to their band gap tunability, giant spin splitting, and valley-related physics. The band structure of TMDCs allows for the detection of valley polarization and optical generation. Layered TMDCs provide unique access to controlling the number of layers and electron valley degree of freedom in k-space in the emerging field of 'valleytronics'. The study shows that a high polarization of the photoluminescence (PL) spectroscopy in TMDCs indicates an optically oriented valley polarization. This is useful for optoelectronic device applications of TMDCs. In Raman and STM spectroscopy, exciton-plasmon coupling and thickness of thin films can be measured through studying changes in the state of polarization of the reflected light from the thin film surface. The objectives of the study include synthesizing TMDCs using solvothermal technique, analyzing exciton and valley effects using photoluminescence spectroscopy, investigating exciton-plasmon coupling in TMDCs, studying optical transition using Raman spectroscopy, and understanding the atomic level Physics of these materials using scanning tunneling microscopy (STM). The synthesis will be done using a solvothermal method, and the work plan includes characterization of 2D transition metal dichalcogenides in mono and multilayer forms. A detailed study of exciton and valley effect using photoluminescence spectroscopy in TMDCs will be conducted, followed by exciton-plasmon coupling and optical transition using Raman spectroscopy and STM in TMDCs. |