Detecting Spin-polarized Valley Carriers in Two-dimensional Transition Metal Dichalcogenides through Perpendicular Magnetic Anisotropic Electrodes
| Autor: | Ting-Ching Chu, 朱庭慶 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Valleyronics, which is a terminology combines valley and electronics, aims to control over the valley degree of freedom in certain semiconductors that possess multiple valleys inside the first Brillouin zone. This extra valley degree of freedom can be combined with electron spin degree of freedom in the system to realize valley-based Spintronic devices that may contribute further applications into industries in the near future. Among various kind of semiconductors, Two-dimensional transition metal dichalcogenides(TMDCs) are candidate materials for valley-based Spintronic devices. The reciprocal lattice of layered 2D-TMDCs are in a honeycomb shape with two set of three-fold valleys, providing electrons an extra valley degree of freedom. Coupled spin and valley polarization of free carriers in the materials facile us to control their spin degree of freedom. In this thesis, we try to detect spin polarized valley carriers in 2D-TMDCs through perpendicular magnetic anisotropy electrodes. Preparation method of monolayer molybdenum disulfide(MoS$_2$) by chemical vapour deposition(CVD) and monolayer tungsten diselenide(WSe$_2$) by mechanical exfoliation onto SiO$_2$/Si substrates are given. Pd/Co and Pt/Co thin film layered structures are grown by e-gun evaporation or sputtering respectively, and their magnetic properties are measured. PMA based valleytronic devices are subsequently fabricated and their properties are dicussed. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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