A Study of the Optical and Electrical Properties of MoSe2 Layered Crystals
| Autor: | SHIH-HUNG CHANG, 張世宏 |
|---|---|
| Rok vydání: | 2002 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 90 Layer single crystals of Mo1-xNbxSe2 have been grown by chemical vapor transport method using Br2 as a transport agent. Detailed characterizations of the material are carried out by using X-ray diffraction, piezoreflectance, absorption, resistivity and Hall effect measurements. X-ray analysis confirms that Mo1-xNbxSe2 are found to crystallize in the hexagonal layered structure. The carrier concentration and carrier type can be obtained directly from the Hall measurement. Optical properties of Mo1-xNbxSe2 were studied via piezoreflectance ( PzR ) measurement at different temperature. The temperature dependence of the exciton transition energy and broadening parameters we analyzed in teams of Varshni and Bose-Einstein expression. The optical absorption measurements reveal that niobium-doped MoSe2 is indirect energy gap semiconductor. The energy gap shows a red shift by increasing the doping concentrations. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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