Nature of polarization in wide-bandgap semiconductor detectors under high-flux irradiation: Application to semi-insulating Cd{sub 1-x}Zn{sub x}Te
- eV PRODUCTS, Compound Semiconductor Group II-VI Inc., Saxonburg, Pennsylvania 16056 (United States)
In this paper, we theoretically investigate the mechanism of polarization in wide-bandgap semiconductor radiation detectors under high-flux x-ray irradiation. Our general mathematical model of the defect structure within the bandgap is a system of balance laws based on carrier transport and defect transition rates, coupled together with the Poisson equation for the electric potential. The dynamical system is self-consistently evolved in time using a high-resolution wave propagation numerical algorithm. Through simulation, we identify and present a sequence of dynamics that determines a critical flux of photons above which polarization effects dominate. Using the experience gained through numerical simulation of the full set of equations, we derive a reduced system of conservation laws that describe the dominant dynamics. A multiple scale perturbation analysis of the reduced system is shown to yield an analytical dependence of the maximum sustainable flux on key material, detector, and operating parameters. The predicted dependencies are validated for 16x16 pixel CdZnTe monolithic detector arrays subjected to a high-flux 120 kVp x-ray source.
- OSTI ID:
- 21070015
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 77, Issue 3; Other Information: DOI: 10.1103/PhysRevB.77.035205; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
ALGORITHMS
CADMIUM COMPOUNDS
CONSERVATION LAWS
DEFECTS
ELECTRIC POTENTIAL
IRRADIATION
PERTURBATION THEORY
POISSON EQUATION
POLARIZATION
SEMICONDUCTOR DETECTORS
SEMICONDUCTOR MATERIALS
SIMULATION
WAVE PROPAGATION
X-RAY DETECTION
X-RAY SOURCES
ZINC COMPOUNDS