Dielectric studies of Cd1-x-yZnxMnyTe crystals and ZnSe1-xTex epilayers

• Main Authors: Hsin Ming Lin, 林新民
• Other Authors: Y. F. Chen
• Format: Others
• Language: en_US
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/91158266721233424707

碩士 === 國立臺灣大學 === 物理學研究所 === 89 === This thesis concerns with the studies on dielectric properties in Cd1-x-yZnxMnyTe crystals and ZnSe1-xTey epilayers. The dielectric properties of these two alloy systems were studied by capacitance and dissipation factor measurements through different temperature and frequency. A Debye-like relaxation of dielectric behavior has been observed, which is found to be a thermally activated process. The activation energies obtained from the capacitance and dissipation factor measurements are in excellent agreement. The relationship between the activation energy and concentration has been established for the first time. The results are described by the four-center model, in which the number of Zn atoms appearing in the nearest-neighbor sites of a defect can have four possible configurations. The frequency dependent conductivity obeys a power law, and the exponent s increases with increasing temperature. The behavior can be explained by polaron tunnelling model. Our results demonstrate that the study of dielectric properties can provide a valueable information for the understanding of defect behavior in semiconductor alloys.