| Time：1130221 (Wed.) 14:20~16:20 Speaker：Prof.林御專(Yu-Chuan Lin) 國立陽明交通大學材料科學與工程學系所/Materials Science and Engineering, National Yang Ming Chiao Tung University Title：Synthesis and Low-Energy Ion Implantation of 2D Transition Metal Dichalcogenides Semiconductors Abstract：Two-dimensional (2D) transition metal dichalcogenides (TMDC) exhibit exciting properties and versatile material chemistry for transistors, optoelectronic devices, quantum information science, and energy missions. Metalorganic chemical vapor deposition (MOCVD) has emerged as a promising technique to grow 2D TMDC due to its ability to carry out high-temperature epitaxial growth and to maintain the ratios of chalcogen/transition metal precursor flows during the process. First, I will discuss our MOCVD process for the growth of 2D TMDC on sapphire and graphene substrates and its capabilities for low-temperature deposition on functionalized surfaces or a damascene structure. Next, I will talk about our recent progress on the substitutional doping of TMDC with Re and V during TMDC growth. Some dopants can modulate carrier concentrations, introduce magnetism, and even heal defects in TMDC. I will also introduce low-energy implantation based on pulsed laser deposition (PLD) that can turn regular TMDC into Janus TMDC, such as MoSSe and WSSe with sulfur on one surface and selenium on the other. This approach can break the symmetry of 2D TMDC to create an out-of-plane dipole moment, which has recently been confirmed by our group. Finally, few-layer-thick TMDC semiconductors might be of interest for device applications to reduce the thermal ionization energy typically too large for room temperature applications in their monolayer counterparts and to improve some aspects of TMDC transistor performance. Toward the end of my talk, I will show how we tailored the MOCVD process to grow epitaxial 2-to-4-layer MoS2, layer-by-layer, on sapphire and the characterization results. Place：B101, Gongguan Campus, NTNU |
