Characterization of CdZnTe and CdTe:Cl materials and their relationship to X- and γ-ray detector performance

Abstract 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 Travelling Heater Methods) as X- and γ-ray detector grade materials by using current-voltage characteristic I ( V ), Thermally Stimulated Current (TSC) and Time of Flight (TOF) measurements. An original TSC technique using X-ray as the light source gives some correlation between electron and hole defect level spectra and the γ-ray detector performances (Zn doping influence, rise time vs. pulse height correlation, ageing effect). A new TOF technique using a N 2 laser gives an idea of the transport properties of free charges and the applied electric field distribution in different detection structures (ohmic contacts or Schottky diodes) whether they are irradiated or not by X-ray (80 keV).