Electric field distribution in Si detectors irradiated with ⁴⁰Ar ions: experimental study and simulation

Abstract

This study is concerned with the influence of defect clusters on the profiles of the electric field E and effective space charge concentration N eff in Si detectors irradiated with 1.62 GeV 40 Ar +7 ions and operating at temperatures from 292 down to 200 K. The electric field profiles reconstructed from the shapes of the detector current pulse response measured by Transient Current Technique demonstrated the double-peak electric field distribution and the inversion of space charge sign on lowering the temperature, all typical of Si detectors irradiated with protons and neutrons. To find a correlation with microscopic parameters specific to the damage induced by ions, the profiles were simulated in terms of the model of two effective deep levels of radiation-induced defects. It is shown that the reconstructed and simulated distributions are in a qualitative agreement; however, simulation required an accurate correction of the deep acceptor parameters and the use of the density of thermally generation current much higher than the experimental value. K: Detector modelling and simulations II (electric fields, charge transport, multiplication and induction, pulse formation, electron emission, etc); Radiation damage to detector materials (solid state); Radiation-hard detectors 1Work carried out in the framework of the CERN-RD50 collaboration. 2Corresponding author.