Imaging performance of single-element CdZnTe detectors for digital radiography

We measured the charge collection efficiency and energy resolution at 60 keV and 122 keV for single-element Cd_0.8Zn_0.2Te semiconductor detectors 2×10×10³ mm irradiated transverse to the electric field, in view of their possible use for digital radiography. Charge collection efficiency, energy resolution and charge collection time have been measured as a function of the bias voltage. The detector´s imaging performance was evaluated, using a scanning procedure, by measurements (at 60 keV) of the line spread function and edge response function of the imaging system; metallic test objects and bone tissue were imaged. Image contrast values as low as C=10% were obtained for a minimum 5:1 S.N.R