Cadmium zinc telluride
Metal alloy

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.[1]

Characteristics

A Cs-137 gamma-ray spectrum collected using an M400 pixelated CZT imaging spectrometer. Energy resolution, as measured by full-width-at-half-maximum (FWHM), is better than 1%.

The CZT band gap varies from approximately 1.4 to 2.2 eV, depending on composition.[2] A 1 cm3 CZT crystal has a sensitivity range of 30 keV to 3 MeV with a 2.5% FWHM energy resolution at 662 keV.[3] Pixelated CZT with a volume of 6 cm3 can achieve 0.71% FWHM energy resolution at 662 keV and perform Compton imaging.[4]

Applications

A YanDavos radiation sensor system based on a 1 cm3 CZT crystal, deployed on a Boston Dynamics Spot quadruped robot for radiation mapping in the Chernobyl Exclusion Zone

Radiation detectors using CZT can operate in direct-conversion (or photoconductive) mode at room temperature, unlike some other materials (particularly germanium) which require cooling or technologies that require a photomultiplier tube.[5] 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.[6] This allows for reduced radiation dosagd, reduced data acquisition time, and small instruments.[5][7]

CZT can be formed into different shapes for different radiation-detecting applications, and a variety of electrode geometries, such as coplanar grids [8] and small pixel detectors,[9] have been developed to provide unipolar (electron-only) operation, thereby improving energy resolution.

Production

Monocrystalline CZT is produced by only a few companies worldwide, with demand exceeding supply in 2025.[1] Furthermore, China placed export controls on CZT in 2025.[10] Consequently, some projects may recycle CZT from other equipment, or use the cadmium telluride as a substitute.[1]

See also

References

  1. ^ a b c "'It's amazing' – the wonder material very few can make". www.bbc.com. 2025-12-12. Retrieved 2025-12-12.
  2. ^ Capper, Peter (1994). Properties of Narrow Gap Cadmium-based Compounds. INSPEC. p. 618. ISBN 0-85296-880-9.
  3. ^ Verbelen, Yannick; Martin, Peter G.; Ahmad, Kamran; Kaluvan, Suresh; Scott, Thomas B. (2021). "Miniaturised Low-Cost Gamma Scanning Platform for Contamination Identification, Localisation and Characterisation: A New Instrument in the Decommissioning Toolkit". Sensors. 21 (8): 2884. Bibcode:2021Senso..21.2884V. doi:10.3390/s21082884. PMC 8074328. PMID 33924123.
  4. ^ Zhang, Feng; Herman, Cedric; He, Zhong; De Geronimo, Gianluigi; Vernon, Emerson; Fried, Jack (2012). "Characterization of the H3D ASIC Readout System and 6.0 cm³ 3-D Position Sensitive CdZnTe Detectors". IEEE Transactions on Nuclear Science. 59 (1): 236. Bibcode:2012ITNS...59..236Z. doi:10.1109/TNS.2011.2175948. S2CID 16381112.
  5. ^ a b "GE Healthcare Acquires CZT Detector Company". Diagnostic and Intervention Cardiology. 15 November 2010. Retrieved 16 December 2025.
  6. ^ 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 (1): 158–161. Bibcode:2011NIMPA.652..158W. doi:10.1016/j.nima.2011.01.144.
  7. ^ Fornell, Dave (15 June 2018). "Nuclear Imaging Moves Toward Digital Detector Technology". Diagnostic and Interventional Cardiology. Retrieved 16 December 2025.
  8. ^ Luke, P.N. (1995). "Unipolar charge sensing with coplanar electrodes -- application to semiconductor detectors". IEEE Transactions on Nuclear Science. 42 (4): 207–213. Bibcode:1995ITNS...42..207L. doi:10.1109/23.467848. S2CID 64754800.
  9. ^ 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. Bibcode:2011JInst...6C2009S. doi:10.1088/1748-0221/6/12/C12009. PMC 3378031. PMID 22737179.
  10. ^ Shaw, Vincent (7 February 2025). "China adds export restrictions for minerals used in thin-film solar". pv magazine. Retrieved 16 December 2025.
  • National Pollutant Inventory - Cadmium and compounds
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