Title :
Development of bulk GaAs room temperature radiation detectors
Author :
McGregor, D.S. ; Knoll, G.F. ; Eisen, Y. ; Brake, R.
Author_Institution :
Dept. of Nucl. Eng., Michigan Univ., Ann Arbor, MI, USA
Abstract :
Various configurations of Schottky diode detectors were fabricated with bulk crystals of liquid encapsulated Czochralski (LEC) semi-insulating undoped GaAs material. Basic detector construction utilized one Ti/Au Schottky contact and one Au/Ge/Ni alloyed ohmic contact. Pulsed X-ray analysis indicated pulse decay times dependent on bias voltage. Pulse height analysis disclosed nonuniform electric field distributions across the width of the detectors, best explained as a consequence of native deep level donors (EL2) in the crystal. Pulse height spectra measured from an /sup 241/Am alpha-particle source at room temperature resulted in a resolution ranging from 2.2% to 3.1% at full width at half maximum (FWHM) for different detectors with a typical resolution of 2.5%. Low-energy gamma rays measured under room-temperature operating conditions resulted in observed full energy peaks of 60 keV and 122 keV photons with measured FWHMs of 22 keV and 40 keV, respectively.<>
Keywords :
Schottky-barrier diodes; alpha-particle detection and measurement; gamma-ray detection and measurement; semiconductor counters; 293 K; Au-Ge-Ni; EL2; GaAs detectors; Schottky diode detectors; Ti-Au; bias voltage; electric field distributions; energy resolution; full width at half maximum; low energy gamma rays; pulse decay times; pulsed X rays; room temperature radiation detectors; Crystals; Energy measurement; Energy resolution; Gallium arsenide; Gold; Pulse measurements; Radiation detectors; Schottky diodes; Space vector pulse width modulation; Temperature;
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference, 1991., Conference Record of the 1991 IEEE
Conference_Location :
Santa Fe, NM, USA
Print_ISBN :
0-7803-0513-2
DOI :
10.1109/NSSMIC.1991.258914
