Monte Carlo simulation for the electron cascade due to gamma rays in semiconductor radiation detectors

Journal Article · Thu Mar 15 00:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3698370· OSTI ID:22038895

Narayan, Raman D; Miranda, Ryan; Rez, Peter ^[1]

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1. Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)

A Monte Carlo code was developed for simulating the electron cascade in radiation detector materials. The electron differential scattering cross sections were derived from measured electron energy-loss and optical spectra, making the method applicable for a wide range of materials. The detector resolution in a simplified model system shows dependence on the bandgap, the plasmon strength and energy, and the valence band width. In principle, these parameters could be optimized to improve detector performance. The intrinsic energy resolution was calculated for three semiconductors: silicon (Si), gallium arsenide (GaAs), and zinc telluride (ZnTe). Setting the ionization thresholds for electrons and holes is identified as a critical issue, as this strongly affects both the average electron-hole pair energy w and the Fano factor F. Using an ionization threshold from impact ionization calculations as an effective bandgap yields pair energies that are well matched to measured values. Fano factors of 0.091 (Si), 0.100 (GaAs), and 0.075 (ZnTe) were calculated. The Fano factor calculated for silicon using this model was lower than some results from past simulations and experiments. This difference could be attributed to problems in simulating inter-band transitions and the scattering of low-energy electrons.

• OSTI ID: 22038895
• Journal Information: Journal of Applied Physics, Vol. 111, Issue 6; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COMPUTERIZED SIMULATION
CROSS SECTIONS
ELECTRONS
ENERGY GAP
ENERGY LOSSES
ENERGY RESOLUTION
ENERGY-LOSS SPECTROSCOPY
FANO FACTOR
GALLIUM ARSENIDES
GAMMA DETECTION
HOLES
IONIZATION
MONTE CARLO METHOD
PHOTOEMISSION
PLASMONS
POLARIZATION
SEMICONDUCTOR DETECTORS
SEMICONDUCTOR MATERIALS
SILICON
ZINC TELLURIDES