HIGH-RESOLUTION NUCLEAR RADIATION DETECTORS FROM EPITAXIAL n-GaAs

Surface barrier p-n junction diodes made from high-purity n-GaAs grown by liquid-phase epitaxy, have been operated as α-particle and low-energy γ-ray detectors over the range 77–373°K. Resolutions observed were 1.2 and 2.95 keV (FWHM) at 130 and 295°K, respectively, for 122-keV γ rays and 30 keV for 5.47-MeV α particles. The energy per electron hole pair for α particles is 4.51 eV and the Fano factor for γ rays is ≤0.24 at 130°K.