Biparametric analyses of charge trapping in Cd{sub 0.9}Zn{sub 0.1}Te based virtual Frisch grid detectors

Journal Article · Thu Feb 21 00:00:00 EST 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4793268· OSTI ID:22102279

Chaudhuri, Sandeep K.; Zavalla, Kelvin J.; Krishna, Ramesh M.; Mandal, Krishna C. ^[1]

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1. Department of Electrical Engineering, University of South Carolina, Columbia, South Carolina 29208 (United States)

Detector grade Cd{sub 0.9}Zn{sub 0.1}Te (CZT) single crystals were grown from zone refined Cd, Zn, and Te ({approx}7 N) precursor materials, using a tellurium solvent method. Detectors with virtual Frisch grid configuration were fabricated using these crystals. I-V measurements revealed low leakage currents at room-temperature, {approx}11 nA for one such detector D1 and {approx}8 nA for another detector D2 at 1100 V. The spectroscopic performances of the two CZT virtual Frisch grid detectors have been evaluated and compared for high energy gamma ray detection. Detector D1 showed a well-resolved pulse-height spectrum with an energy resolution of {approx}1.6% for the 662 keV gamma rays. Detector D2 also showed a distinct 662 keV peak but with a broader pulse-height distribution. A digital biparametric correlation study of the depth of interaction and energy deposited by the 662 keV gamma rays was carried out. A different kind of correlation pattern from that observed normally for hole trapping was noticed in the case of detector D2. Correlation of results from thermally stimulated current measurement studies suggested that the anomalous biparametric correlation pattern was due to the trapping of holes but modified by the virtual Frisch grid effect. The results also suggested that the effect of electron trapping could not be ruled out either. Finally, a digital correction scheme was applied to recover the {sup 137}Cs spectrum from the effect of charge loss.

• OSTI ID: 22102279
• Journal Information: Journal of Applied Physics, Vol. 113, Issue 7; Other Information: (c) 2013 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CADMIUM COMPOUNDS
CESIUM 137
DISTRIBUTION
ELECTRIC CONDUCTIVITY
ENERGY RESOLUTION
GAMMA DETECTION
GAMMA RADIATION
INTERACTIONS
KEV RANGE 100-1000
LEAKAGE CURRENT
MONOCRYSTALS
SEMICONDUCTOR DETECTORS
SEMICONDUCTOR MATERIALS
SPECTRA
TELLURIUM COMPOUNDS
TEMPERATURE RANGE 0273-0400 K
X-RAY DETECTION
ZINC COMPOUNDS