Next Generation Semiconductor-Based Radiation Detectors Using Cadmium Magnesium Telluride

At present, CdZnTe is considered the material of choice for efficient, room temperature gamma-radiation detection systems used for the detection and identification of radionuclides. Despite the advances in CdZnTe materials technology during the last decade, the major impediments in the progress of - ray detection technology are the low yield of device quality materials and detectors, and the limited availability of such detectors in large quantities at reasonable cost. Therefore, there is a strong need to develop an alternate wide band gap semiconductor material for more rapid advancement in gamma ray detection technology. We propose an innovative wide band-gap semiconductor, CdMgTe, which has several advantages over CdZnTe. In an effort to develop CdMgTe as a potential gamma-ray detector material, we propose to perform extensive studies to gain a clear understanding of the basic material properties and their relation to material performance. Through these studies we will determine the optimum growth and doping techniques that result in high quality CdMgTe crystals with the characteristics that are essential for room temperature gamma-radiation detection: high resistivity, good compositional homogeneity, and good electron-hole transport properties. Commercial Applications and Other Benefits: The proposed room temperature gamma-radiation detection system can be used in a variety of commercial applications including elemental analysis, explosive detection, medical diagnostics, x-ray imaging, seismic activity detection, and radiation monitoring. The proposed material system will lead to a new generation of lower cost, portable detectors for nuclear physics research. These detectors are expected to have high-energy resolution and high detection efficiency in a rugged and portable package. Also, at the present time, bulk CdMgTe crystals are not available commercially, and we hope to become a domestic source for this material as an eventual outcome of this research.