Dilute magnetic semiconductors based on ZnO
| Autor: | Chia-Lung Tsai, 蔡佳龍 |
|---|---|
| Rok vydání: | 2012 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 100 In this study, Zn1-xCoxO, Zn0.962-yCo0.038MgyO (ZnCoMgO) and Zn0.962-gCo0.038AlgO films were deposited on substrates by the Sol-gel method. Optical, electrical, magnetic properties and structural characterizations were in-vestigated using suitable techniques including photoluminescence (PL), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), alternating gradient magnetometer (AGM). The electrical properties of Au/In/ZnCoMgO/In/Au device, Au/In/ ZnCoMgO/p-Si/Au and Au/In/ZnCoMgO/p+-Si/Au Metal-Oxide-Semiconduc-tor (MOS) capacitors were investigated by semiconductor characterization sys-tem. According to the experimental results, the grain boundaries and lattice dis-tortion due to Zn vacancy defect plays an essential role for the ferromagnetism (FM) in ZnO dilute magnetic semiconductor. The hysteresis mechanism in cur-rent-voltage characteristics of Au/In/ZnCoMgO/In/Au device has been found and was investigated through trapping/detrapping of charges in the ZnCoMgO films. The relationship between the conduction mechanism and defect in ZnCoMgO films for Au/In/ZnCoMgO/n-Si/Au MOS capacitors were analyzed in this study. The relative permittivity and trap energy level was also obtained in differenet conduction mechanisms. By using FM in ZnCoMgO films, charge trapping of the memory window was demonstrated. When a magnetic field was applied, the capacitor of this MOS device which the flat-band voltage was in-creaced, causing the memory window to become large.These results suggest that ZnCoMgO films can be used for spin-functional memory device. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|