A mechanism for dynamic lateral polarization in CdZnTe under high flux x-ray irradiation

It has been observed that pixillated CdZnTe detectors fabricated from crystals with low hole transport properties (mu(h) tau(h) < 10(-5) cm(2) V-1) experience a dynamic lateral polarization when exposed to a high flux of x-rays. In this effect, counts are transferred from pixels near the edge of the irradiated region to pixels in the interior. In this letter, we propose a mechanism capable of explaining the observed dynamical effect. The mechanism is based on a transverse electric field that is generated due to space charge that builds within the material. This transverse field, in turn, is responsible for the altered carrier trajectories toward the center of the irradiated region. (C) 2008 American Institute of Physics.