Effect of barrier contacts on carrier transport in homogeneous GaAs structures doped with deep Cr and EL$_2$ centers

We report on the results of investigations of carrier transport in GaAs structures doped with the EL$_2$ deep donor centers and Cr acceptor levels for ionizing radiation detectors and ultrafast photoelectric switches. Structures of three configurations: $p$–$i$–$n$, $n$–$i$–$n$, and $p$–$i$–$p$, are examined. A system of differential equations for the carrier temperature and Poisson’s and continuity equations is solved using commercial software. It is found that, choosing the barrier-layer type, one can control the electric-field-strength uniformity in the structures. It is shown that the $p$–$i$–$p$ structures exhibit the best uniformity of the electric-field strength.