9802712 Lynn This University/Industry collaborative GOALI project aims for greater understanding of the nature and properties of the defects governing the electrical and carrier trapping properties of semi- insulating(SI) CdZnTe. The approach involves systematic study of lattice defects in high-purity SI CdZnTe grown from melt by Bridgman techniques in order to understand their role in electrical compensation and carrier trapping. Doping and growth experiments with thermally stimulated and positron annihilation spectroscopies will be combined to identify defects and determine their trapping parameters. The incorporation of selected impurities and the formation of defects as a function of growth conditions will be studied to determine key thermodynamic parameters controlling defect formation and incorporation. The concentration of impurities will be measured by glow-discharge mass spectroscopy and resonance-ionization enhanced mass spectroscopy and correlated with thermal spectroscopies and positron annihilation. Infrared microscopy and absorption will be used to study the formation of Cd and Te precipitates and their effect on the incorporation of impurities and the formation of defect complexes. Annealing experiments will be conducted to shed study diffusion properties of dominant defects and provide a better understanding of defect diffusion and formation during cooling of the crystals following solidification. The project is co-supported by the DMR Electronic Materials Program and the MPS OMA(Office of Multidisciplinary Activities). %%% Basic research issues in a topical area of materials science having technological relevance are addressed by this project. The basic knowledge and understanding gained from the research is expected to contribute to improving the performance and stability of advanced devices by providing a fundamental understanding and a basis for designing and producing improved materials, and materials combinations. An important feature of the program is the integration of research and education by providing an important educational opportunity through the GOALI aspect of the project for academic personnel to experience both academic and industrial research approaches and environments. ***
