CHARACTERIZATION OF CDZNTE AND CDTE-CL MATERIALS AND THEIR RELATIONSHIP TO X- AND GAMMA-RAY DETECTOR PERFORMANCE

The aim of this work is to qualify CdTe and CdZnTe (grown by the High Pressure Bridgman Method) and CdTe:Cl (grown by the Bridgman and Trave lling Heater Methods) as X- and gamma-ray detector grade materials by using current-voltage characteristic I(V), Thermally Stimulated Curren t (TSC) and Time of Flight (TOF) measurements. An original TSC techniq ue using X-ray as the light source gives some correlation between elec tron and hole defect level spectra and the gamma-ray detector performa nces (Zn doping influence, rise time vs. pulse height correlation, age ing effect). A new TOF technique using a N-2 laser gives an idea of th e transport properties of free charges and the applied electric field distribution in different detection structures (ohmic contacts or Scho ttky diodes) whether they are irradiated or not by X-ray (80 keV).