Radiation hardness of GaAs: Cr and Si sensors irradiated by electron beam

TL;DR

This study investigates the radiation hardness of GaAs:Cr sensors under electron beam irradiation, comparing their performance with silicon sensors to evaluate their suitability for high-radiation environments.

Contribution

It provides the first systematic experimental analysis of GaAs:Cr sensors' radiation effects at high doses, including microscopic mechanism insights.

Findings

GaAs:Cr sensors maintain high resistivity after irradiation

Charge collection efficiency decreases with dose

Comparison shows GaAs:Cr outperforms silicon in radiation hardness

Abstract

The interest in using the radiation detectors based on high resistive chromium-compensated GaAs (GaAs:Cr) in high energy physics and others applied fields has been growing steadily due to its numerous advantages over others classical materials. High radiation hardness at room temperature stands out and needs to be systematically investigated. In this paper an experimental study of the effect of 20.9 MeV electrons generated by the LINAC-200 accelerator on some properties of GaAs:Cr based sensors is presented. In parallel, Si sensors were irradiated at the same conditions, measured and analyzed in order to perform a comparative study. The target sensors were irradiated with the dose up to 1.5 MGy. The current-voltage characteristics, resistivity, charge collection efficiency and their dependences on the bias voltage and temperature were measured at different absorbed doses. An analysis of the possible microscopic mechanisms leading to the observed effects in GaAs:Cr sensors is presented in the article.