Study on Electronic Properties of II-VI Diluted Magnetic Semiconductors

• Main Authors: Chao-Lung Chang, 張朝榮
• Other Authors: D. S. Chuu
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/95553171421199912027

碩士 === 國立交通大學 === 電子物理系 === 88 === By using the program of CASTEP (Cambridge Series Total Energy Package) based on the first-principle theory, we have studied the phase transitions of ZnSe and CdSe under high pressure. The result shows that the structure of ZnSe will be transformed from zinc-blende to cinnabar, and become the rocksalt structure as the presssure is increased. It is found that the structure of CdSe is directly transformed from zinc-blende into rocksalt. And the frequencies and modes of LO and TO phonons in CdSe are obtained. Besides, we have also calculated the electronic structures and density of states of the DMS compounds Cd1-xFexSe which is resulted from the partial substitution of Fe into the site of Cd in CdSe. It is found the volume of the unit cell of Cd1-xFexSe decreases when the concentration fraction x is increased. The amplitudes and the positions of peaks of density of states are changed with respect to the fraction x.