CapeSym develops novel processing and growth techniques for the production of high quality radiation detection materials such as CADMIUM ZINC TELLURIDE (CZT). CapeSym also currently grows crystals of STRONTIUM IODIDE (SrI2(Eu)), and THALLIUM BROMIDE (TlBr).

In addition, CapeSym has a number of characterization and testing tools in-house. Click HERE to learn more about our tools and services.


Cadmium Zinc Telluride

CADMIUM ZINC TELLURIDE (CZT) radiation detectors offer a number of unrivaled advantages in medical imaging and security inspection. In medical imaging, high resolution images can be obtained at substantially lower irradiation doses than required by scintillator-based detectors. In security inspection, the high energy resolution, sensitivity, and imaging speed achievable by CdZnTe detectors allow for unambiguous identification of dirty bombs, contraband nuclear materials, as well as monitoring nuclear proliferation across borders.

CapeSym has invested years in developing its process for production of CdZnTe gamma detectors. CapeSymís process has a very high yield of materials with superior performance characteristics that enables development of cost- effective radiation detector equipment.

CZT Detector

Strontium Iodide

SrI2(Eu) Detector

Europium-doped STRONTIUM IODIDE (SrI2(Eu)) gamma detectors have a very high light output and an energy resolution of about 3% at 662keV, much better than the incumbent NaI(Tl) and CsI(Tl) scintillators. To date, availability of SrI2 detectors has been severely limited by the fracture of the crystal during crystal growth, resulting in low yield and high prices.

CapeSymís proprietary crystal growth process has overcome the fracture problem and is now routinely producing 1-in diameter crystals. CapeSymís patent-pending process is based on decades of experience in crystal growth, crystal growth process simulation, and fracture mechanics. Scale up to 2-in and larger diameter crystals is in progress.

Thallium Bromide

THALLIUM BROMIDE (TlBr) is a promising room temperature gamma radiation semiconductor detector material, primarily due to its high Z component and high density. It has higher photoelectric and total attenuation coefficients than other semiconductor detectors for gamma-rays with energy greater than 20 keV. For example, the attenuation length of 662 keV photons incident on TlBr is 1.4 cm, significantly shorter than that for CZT (2.3 cm).

Ultra high purity TlBr detector grade crystals are routinely produced at CapeSym using Travelling Molten Zone (TMZ) and Vertical Bridgman Techniques. Capesym can provide single crystalline TlBr detector grade devices up to 4cc in volume. As this is a toxic material, fabrication of these devices need special instructions. CapeSym has a dedicated facility to fabricate and deliver custom (shape, size, surface treatment, metal contacts etc.) ready-to-use TlBr devices for research purposes. Innovative characterization technique have been developed and deployed to quantify and correlate surface (including metallic contact) and bulk defects in ionic TlBr semiconductor. The details of this tool can be found HERE.

Thallium Bromide Detector 1
Thallium Bromide Detector 2

Additional Materials

Our R&D portfolio of pre-commercialization materials also include

Semiconductors for

  • Gamma-ray detection (CdZnTe, CdMnTe, TlBr)
  • Neutron detection (LiInSe2)
  • Infra-red substrates (CdZnTe, GaSb)
  • High power devices (SiC)
  • Scintillators for

  • Gamma-ray detection (alkali iodide and bromide and rare-earth metals)
  • Neutron detection (elpasolites, 6Li-compounds)

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