Study on electric field in Au/CdZnTe/In detectors under high fluxes of X-ray and laser irradiation

Abstract

We used simultaneous Pockels effect and photoconductivity measurements to study of processes in high-resistivity CdZnTe semiconductor X-ray and gamma ray detector material at steady state high flux conditions. We have proven, that with an appropriate choice of monochromatic laser light, the profile of the electric field is nearly the same as with a polychromatic X-ray source. We observed that the electric field is strongly deformed in the case of both above and below bandgap laser radiation. This leads to a decrease of the photocurrent when the sample is illuminated with above bandgap radiation. When below bandgap illumination is used the photocurrent values are not affected by electric field weakening. This is explained by increased filling of the midgap trap with trapped electrons leading to an increase of the lifetime.