BULK GAAS ROOM-TEMPERATURE RADIATION DETECTORS

Bulk GaAs, a wide band gap semiconductor, shows potential as a room temperature radiation detector. Schottky diode detectors were fabricated from LEC bulk GaAs crystals. The basic construction of these diodes employed the use of a Ti/Au Schottky contact and a Au/Ge/Ni alloyed ohmic contact. Pulse height characteristics of these diodes indicate active regions of more than 100 mum. Pulse height spectra were recorded from alpha particle irradiation of the Schottky contact surface resulting in a best energy resolution of 2.5% at 5.5 MeV. Low energy gamma rays measured under room temperature operating conditions resulted in photopeaks with 37% FWHM at 60 keV.