Cadmium zinc telluride

Cadmium zinc telluride, (CdZnTe) or CZT, is a compound of cadmium, zinc and tellurium or, more strictly speaking, an alloy of cadmium telluride and zinc telluride. A direct bandgap semiconductor, it is used in a variety of applications, including semiconductor radiation detectors, photorefractive gratings, electro-optic modulators, solar cells, and terahertz generation and detection. The band gap varies from approximately 1.4 to 2.2 eV, depending on composition.

Radiation detectors using CZT can operate in direct-conversion (or photoconductive) mode at room temperature, unlike some other materials (particularly germanium) which require liquid nitrogen cooling. Their relative advantages include high sensitivity for x-rays and gamma-rays, due to the high atomic numbers of Cd and Te, and better energy resolution than scintillator detectors.^[1] CZT can be formed into different shapes for different radiation-detecting applications, and a variety of electrode geometries, such as coplanar grids ^[2] and small pixel detectors,^[3] have been developed to provide unipolar (electron-only) operation, thereby improving energy resolution.

References

^ Wilson, Matthew David; Cernik, Robert; Chen, Henry; Hansson, Conny; Iniewski, Kris; Jones, Lawrence L.; Seller, Paul; Veale, Matthew C. (2011). "Small pixel CZT detector for hard X-ray spectroscopy". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 652: 158–161. doi:10.1016/j.nima.2011.01.144.
^ Luke, P.N. (1995). "Unipolar charge sensing with coplanar electrodes -- application to semiconductor detectors". IEEE Transactions on Nuclear Science. 42 (4): 207–213. doi:10.1109/23.467848.
^ Seller, P.; Bell, S.; Cernik, R. J.; Christodoulou, C.; Egan, C. K.; Gaskin, J. A.; Jacques, S.; Pani, S.; Ramsey, B. D.; Reid, C.; Sellin, P. J.; Scuffham, J. W.; Speller, R. D.; Wilson, M. D.; Veale, M. C. (2011). "Pixellated Cd(Zn)Te high-energy X-ray instrument". Journal of Instrumentation. 6 (12): C12009. doi:10.1088/1748-0221/6/12/C12009. PMC 3378031. PMID 22737179.

Properties of Narrow-Gap Cadmium-Based Compounds Ed. P. Capper (INSPEC, IEE, London, UK, 1994) ISBN 0-85296-880-9

External links

National Pollutant Inventory - Cadmium and compounds

[1] Wilson, Matthew David; Cernik, Robert; Chen, Henry; Hansson, Conny; Iniewski, Kris; Jones, Lawrence L.; Seller, Paul; Veale, Matthew C. (2011). "Small pixel CZT detector for hard X-ray spectroscopy". Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 652: 158–161. doi:10.1016/j.nima.2011.01.144.

[2] Luke, P.N. (1995). "Unipolar charge sensing with coplanar electrodes -- application to semiconductor detectors". IEEE Transactions on Nuclear Science. 42 (4): 207–213. doi:10.1109/23.467848.

[3] Seller, P.; Bell, S.; Cernik, R. J.; Christodoulou, C.; Egan, C. K.; Gaskin, J. A.; Jacques, S.; Pani, S.; Ramsey, B. D.; Reid, C.; Sellin, P. J.; Scuffham, J. W.; Speller, R. D.; Wilson, M. D.; Veale, M. C. (2011). "Pixellated Cd(Zn)Te high-energy X-ray instrument". Journal of Instrumentation. 6 (12): C12009. doi:10.1088/1748-0221/6/12/C12009. PMC 3378031. PMID 22737179.

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