Gamma ray spectrometers fabricated from modified Bridgman/annealed CZT crystal material

Book · Thu Dec 31 04:00:00 EST 1998

OSTI ID:323836

Chattopadhyay, K; Chen, H; Chen, K T; Burger, A ^[1]; Flint, J P; Glass, H L ^[2]; James, R B ^[3]

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1. Fisk Univ., Nashville, TN (United States). Center for Photonic Materials and Devices
2. Johnson Matthey Electronics, Spokane, WA (United States)
3. Sandia National Labs., Livermore, CA (United States). Advanced Electronics Manufacturing Technologies Dept.

The CZT boule was grown by a modified vertical Bridgman process using in-situ compounding, Cd over-pressure and a pyrolytic boron nitride crucible within a fused ampoule. During growth, the Cd vapor pressure was near 1 atmosphere. These growth conditions tend to give high purity, good stoichiometry, few precipitates, and dislocation densities in the low to mid-10{sup 4} cm{sup {minus}2} range. The crystals, after polishing, were annealed in a nearly saturated Cd, Zn atmosphere to fill residual Cd-site vacancies and achieve high resistivity in the 10{sup 10} {Omega}-cm range. Low temperature photoluminescence study shows very good crystalline quality and a very low concentration of deep level recombinations. Single crystal samples were diced into 1 cm squares for evaluation as gamma ray detectors. The best detector results (4.5% resolution at 60 keV) were achieved for a 2 hour anneal at 850 C.

• Sponsoring Organization: National Aeronautics and Space Administration, Washington, DC (United States); USDOE, Washington, DC (United States)
• OSTI ID: 323836
• Report Number(s): CONF-971201--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
AMBIENT TEMPERATURE
BRIDGMAN METHOD
CADMIUM TELLURIDES
CRYSTAL DEFECTS
ELECTRICAL PROPERTIES
EXPERIMENTAL DATA
GAMMA SPECTROMETERS
SEMICONDUCTOR DETECTORS
SPECTRAL RESPONSE
ZINC TELLURIDES