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We describe energy-dependent incomplete signal generation in semiconductor detectors with a simple planar geometry using deep charge trapping and depth-of-interaction models. Based on this formalism, we have characterized mercuric iodide (HgI_2) photoconductors by extracting performance parameters from x-ray-induced signals under mammographic imaging conditions. The HgI_2 sample photoconductors were prepared using a simple screen-printing method. For an x-ray tube output from tungsten target and 30-kV setting, the quantum absorption efficiency of samples with a thickness of approximately 0.1 mm was measured to be \sim 70\%. X-ray sensitivity was measured to be 0.4~\nC cm^ - 2 mR^ - 1. Mobility-lifetime products for electrons and holes were measured as \sim 2 \times 10^ - 6~\cm^2~\V^ - 1 and \sim 0.9 \times 10^ - 6~\cm^2~\V^ - 1, respectively. Considering incomplete charge collection, the W-value (or w) was estimated to be \sim 27 ~\eV. Since the characterization method described in this study is simple and does not require sophisticated equipment, it can be useful for the characterization of photoconductor materials. [ABSTRACT FROM AUTHOR]

Films of HgBrI (eutectic composition) were grown by the physical vapor deposition method on palladium-coated glass substrates 2''times2'' in size. The growth was performed in a system especially designed and constructed for getting a fine control of the growth parameters. The best growth conditions were a source temperature of 116degC, a growth temperature of 40degC and a growth time of 3 h, with an initial pressure of 6times10-3 Pa. Film thicknesses and grain sizes gave values ranging between 100 and 350 mum (10%), and between (10plusmn5) and (50plusmn20) mum, respectively. The dark current density of the films is higher than 10 pA/mm2 (maximum value required for the application) for electric fields above 0.03 V/mum, and the resistivity is 3.8times1011 Omega.cm. Electron and hole mobility-lifetimes of 7.1times10-6 cm2/V y 1.0times10-5 cm2/V were estimated. HgBrI films give a sensitivity to X-rays of 65 nC/Rmiddotcm2 for an X-ray beam of 70 KVp, with an electric field of 0.25 V/mum applied to the film. Taking into account that this is the first attempt on growing films with this material, these results indicate HgBrI as a new compound semiconductor candidate for the application [ABSTRACT FROM PUBLISHER]