A Polycrystalline CdZnTe Film and Its X-ray Response Characteristics for Digital Radiography

The Cd1-x/Znx/Te film was produced by thermal evaporation for the flat-panel X-ray detector. The crystal structure and the surface morphology of poly crystalline Cd1-x/Znx/Te film were examined using XRD and SEM, respectively. The leakage current and X-ray sensitivity of the fabricated films were measured to analyze the X-ray response characteristic of Zn in a polycrystalline CdZnTe thin film. The leakage current and the output charge density of Cd0.7/Zn0.3/Te thin film were measured to 0.3 1nA/ and 260 pC/ at an applied voltage of 2.5 V/, respectively. Experimental results showed that the increase of Zn doping rates in Cd1-x/Znx/Te detectors reduced the leakage current and improved the X-ray sensitivity significantly. The leakage current was drastically diminished by the formation of thin parylene layer in the Cd0.7/Zn0.3/Te detector.