Modelization of epitaxial GaAs X-ray detectors

X-ray detectors are fabricated with non-intentionally doped thick epitaxial GaAs layers grown by a chemical technique. They are p+/i/n+ structures in which the highly doped p- and n-type layers are made by ion implantation on both faces of the i epilayers. In order to understand the behaviour of charge collection, we modelize the capacitance–voltage characteristics of such structures, which are then compared with experimental data.