Real-time Pockels imaging is performed on semi-insulating CdZnTe to measure the electric field profile in the material bulk. In steady-state room temperature conditions the measured electric field profile is uniform, consistent with a low space charge concentration. At temperatures $<270\text{K}$ a significant nonuniform electric field profile is observed, which we explain in terms of temperature-induced band bending at the metal-semiconductor interface, causing the formation of positive space charge in the bulk. Similar electric field distortion effects are observed when room temperature CdZnTe is irradiated by x-rays, causing a high rate of photoinduced charge injection.

CdTe and (Cd,Zn)Te crystals were grown to study the compensation mechanism and the influence on the transport properties. Undoped and doped crystals with Sn, In, and Ge were grown. The crystals showed resistivities up to 10/sup 9/ /spl Omega/cm and higher. The transport properties depended strongly on the dopant and the compensation mechanism. For the doping with a deep donor, the mobility-lifetime product of electrons were 2/spl times/10/sup -5/ cm/V and 4/spl times/10/sup -4/ mcm/sup 2//V for Ge and Sn doped, respectively. The highest values were obtained for In doped (Cd,Zn)Te with 3.3/spl times/10/sup -3/ cm/sup 2//V.