Cadmium Manganese Telluride (Cd1-xMnxTe): A potential material for room-temperature radiation detectors

Conference · Sun Jul 11 00:00:00 EDT 2010

OSTI ID:1013493

Hossain, A; Cui, Y; Bolotnikov, A; Camarda, G; Yang, G; Kim, K-H; Gul, R; Xu, L; Li, L; Mycielski, A; and James, R B

Cadmium Manganese Telluride (CdMnTe) recently emerged as a promising material for room-temperature X- and gamma-ray detectors. It offers several potential advantages over CdZnTe. Among them is its optimal tunable band gap ranging from 1.7-2.2 eV, and its relatively low (< 50%) content of Mn compared to that of Zn in CdZnTe that assures this favorable band-gap range. Another important asset is the segregation coefficient of Mn in CdTe that is approximately unity compared to 1.35 for Zn in CdZnTe, so ensuring the homogenous distribution of Mn throughout the ingot; hence, a large-volume stoichiometric yield is attained. However, some materials issues primarily related to the growth process impede the production of large, defect-free single crystals. The high bond-ionicity of CdMnTe entails a higher propensity to crystallize into a hexagonal structure rather than to adopt the expected zinc-blend structure, which is likely to generate twins in the crystals. In addition, bulk defects generate in the as-grown crystals due to the dearth of high-purity Mn, which yields a low-resistivity material. In this presentation, we report on our observations of such material defects in current CdMnTe materials, and our evaluation of its potential as an alternative detector material to the well-known CdZnTe detectors. We characterized the bulk defects of several indium- and vanadium-doped Cd1-xMnxTe crystals by using several advanced techniques, viz., micro-scale mapping, white-beam x-ray diffraction/reflection topography, and chemical etching. Thereafter, we fabricated some detectors from selected CdMnTe crystals, characterized their electrical properties, and tested their performance as room-temperature X- and gamma-ray detectors. Our experimental results indicate that CdMnTe materials could well prove to become a viable alternative in the near future.

• Research Organization: Brookhaven National Lab. (BNL), Upton, NY (United States)
• Sponsoring Organization: DOE - National Nuclear Security Administration
• DOE Contract Number: DE-AC02-98CH10886
• OSTI ID: 1013493
• Report Number(s): BNL-93721-2010-CP; R&D Project: 10406; 10406; NN2001000; TRN: US1102488
• Resource Relation: Conference: 51st Annual Meeting, Institute of Nuclear Materials Management; Baltimore, Maryland; 20100711 through 20100715
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
CADMIUM
DEFECTS
DISTRIBUTION
ELECTRICAL PROPERTIES
ETCHING
EVALUATION
INDIUM
MANGANESE TELLURIDES
MONOCRYSTALS
NUCLEAR MATERIALS MANAGEMENT
PERFORMANCE
PRODUCTION
RADIATION DETECTORS
SEGREGATION
TOPOGRAPHY
CdMnTe
detectors
IR microscopy
etch pit density
cellular network
mobility-lifetime product