A study of the trap influence on the performance of semi-insulating GaAs detectors

A numerical approach has been used to describe the influence of the traps on the properties of semi-insulating GaAs detectors. Based on a realistic trap scheme, the electric field distribution and the active region thickness in GaAs detectors have been calculated and compared with experimental results. From the electric field distribution and the concentration of ionized traps, taking into account detrapping processes, the carrier mean free path has been calculated and used to evaluate the charge collection efficiency. cessity to consider the role of the high-electric-field effects on the stationary occupation of traps clearly comes out from this analysis.