Estimation of the energy resolution limit for particle detectors with schottky-barrier based on VPE GaAs

This paper reports the results of the characterization of detectors based on high purity VPE GaAs with an active area of 25 and 80 mm
²
for the detection of nuclear reaction products at interactions between heavy ions and light nuclei. The detectors have demonstrated a high FWHM of 14.5 and 15.5 keV for 25 and 80 mm
²
, respectively (5.499 MeV line of
²³⁸
Pu). Various components of the total energy resolution were analysed in order to estimate the energy resolution limit of the detectors. It was shown that the energy loss straggling of α-particles in the dead layer is the main contribution to the energy resolution of the studied detectors. Thus, the optimization of the Pt Schottky contact formation process can make it possible to improve the energy resolution (by 1-2 keV) of the VPE GaAs detectors.