Cadmium zinc telluride
Metal alloy
From Wikipedia, the free encyclopedia
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
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
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 dosage, 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]