Dissertation
Optimization of cadmium zinc telluride crystal growth for room temperature radiation detectors
Washington State University
Doctor of Philosophy (PhD), Washington State University
12/2009
DOI:
https://doi.org/10.7273/000006109
Abstract
Solid state semiconductor room temperature radiation detectors are important for the Department of Homeland Security and medical imaging applications. Cadmium zinc telluride (CZT) is a promising semiconductor material for room temperature radiation detectors and many other uses because of its large band gap, charge carrier mobilities and atomic number. Crystal growth of CZT is being performed and characterized for room temperature radiation detectors around the world. Optimizing the crystal growth parameters for large volume (>6cm3) detectors is critical for national security applications and nuclear nonproliferation. The non-stoichiometry of the II-VI semiconductors and the complexity of the bulk crystal growth process produce low usable yields. To fully optimize CZT detectors, understanding and controlling every step in the crystal fabrication process is essential. This dissertation presents steps and discoveries to optimize a modified low pressure vertical Bridgman crystal growth process to result in a large volume well compensated CZT material that functions as a room temperature radiation detector. Careful attention to compensation and nonuniformity will be presented. Grown ingots have been characterized by current-voltage measurements, infrared microscopy, mu tau product and response to absorbing radiation using a Multi-Channel Analyzer (MCA). Results achieved resolution of less than 2% at 662 keV and mu tau product greater than 1x10-2 cm2 /V.
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Details
- Title
- Optimization of cadmium zinc telluride crystal growth for room temperature radiation detectors
- Creators
- Kelly Allan Jones
- Contributors
- Kelvin G. Lynn (Chair)Matthew D. McCluskey (Committee Member) - Washington State University, Department of Physics and AstronomyM Grant Norton (Committee Member) - Washington State University, Honors CollegeDavid P Field (Committee Member) - Washington State University, School of Mechanical and Materials Engineering
- Awarding Institution
- Washington State University
- Academic Unit
- Materials Science and Engineering Program
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 147
- Identifiers
- 99901055020501842
- Language
- English
- Resource Type
- Dissertation