Sensitivity reduction mechanisms in amorphous selenium photoconductive x-ray image detectors

Journal Article · Mon Dec 27 00:00:00 EST 2004 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.1841474· OSTI ID:20634586

Yunus, M; Kabir, M Zahangir; Kasap, S O ^[1]

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1. Department of Electrical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada)

Sensitivity reduction in amorphous Se-based photoconductive x-ray image detectors due to previous exposures is studied by Monte Carlo simulation. Collected charge, hence x-ray sensitivity, is calculated by considering deep carrier trapping, taking into account the effects of trap filling, recombination between trapped and drifting carriers and the generation of x-ray induced new deep trap centers. Space charge effects on the electric field, and hence, the effects of electric field on electron hole pair generation and charge transport are also considered. The comparison of the model with the experimental data reveals that the recombination between trapped and oppositely charged drifting carriers and x-ray induced new deep trap centers are mainly responsible for the sensitivity reduction in biased a-Se-based x-ray detectors.

• OSTI ID: 20634586
• Journal Information: Applied Physics Letters, Vol. 85, Issue 26; Other Information: DOI: 10.1063/1.1841474; (c) 2004 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CHARGE TRANSPORT
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
ELECTRIC FIELDS
ELECTRONS
EXPERIMENTAL DATA
HOLES
IMAGES
MONTE CARLO METHOD
RECOMBINATION
SELENIUM
SEMICONDUCTOR MATERIALS
SENSITIVITY
SPACE CHARGE
TRAPPING
TRAPS
X RADIATION