X-ray DC response of a simple photoconductive detector based on CdZnTe film

CdZnTe thin films were deposited on glass substrates by close-spaced sublimation method and then annealed in vacuum. The structure, morphology and composition are investigated by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, respectively. The CdZnTe film detector shows a linear X-ray response, which is about one order of magnitude lower than that of the single crystalline CdZnTe sample. The mobility and lifetime product of the CdZnTe film is estimated to be around 6.5 × 10−6cm2/V. Time dependent X-ray response shows the increase of photocurrent with time at the first 20 min for the film detector, indicating a filling of traps in the forbidden gap.