<title>Optical studies of the internal electric field distributions, crystal defects, and detector performance of CdZnTe radiation detectors</title>

Abstract

Polarized transmission optical profiles were employed to characterize the CdZnTe (CZT) room-temperature radiation detectors. 2D images reflecting the internal electric field intensity changes were obtained utilizing the Pockels electro-optic effect. Varieties of different types of CZT detectors, i.e., planar and P-I-N detectors, were investigated under different operating bias voltages, respectively. Single crystal and polycrystalline CZT detectors were also studied and compared. Nonuniform internal electric field distributions throughout the detector volumes were observed and analyzed. The grain- boundary effects to the internal electric fields will be presented and discussed, along with a theoretical simulation. A semiconductor energy band model associated with depletion layer width will be emphasized and discussed.