Crystal Growth and Characterization of Mo1-xNbxS2 Transition Metal Dichalcogenide
碩士 === 國立臺灣科技大學 === 電子工程系 === 102 === Single crystals of Mo1-xNbxS2 have been grown by chemical vapor transport method using Iodine as a transport agent. These series platelets up to 1.5×1.5 cm2 surface area and 0.2~0.3 cm in thickness be obtained. X-ray diffraction patterns show two-layered hexagon...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2014
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| Online Access: | http://ndltd.ncl.edu.tw/handle/61319414714727634755 |
| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 102 === Single crystals of Mo1-xNbxS2 have been grown by chemical vapor transport method using Iodine as a transport agent. These series platelets up to 1.5×1.5 cm2 surface area and 0.2~0.3 cm in thickness be obtained. X-ray diffraction patterns show two-layered hexagonal primitive unit cell (2H) for molybdenum disulfide and three-layered rhombohedral primitive unit cell (3R) for niobium disulfide. The effect for all niobium-doped samples are an increase in lattice a and a decrease in lattice c, which led to a increase of the cell volumes. The co-existence on basal plane for both 2H-type and 3R-type vibration active-mode were observed by polarization dependent Raman scattering. With substituted Nb concentration increase, all vibration active-mode of series compounds are shifting to low-frequency, which reveal parabolic relation.
Molybdenum disulfide belongs to semiconductor whereas niobium disulfide belongs to metallic compound. It is found that linear trend of conductivity due to doped-Nb concentration increase. Temperature dependent resistivity for each compound shows the progress of semiconductor-metal transition. The critical composition happened on x ≈ 0.1 to transfer from semiconductor to metallic characteristic.
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