Reviewing polycrystalline mercuric iodide X-ray detectors

Polycrystalline films of HgI₂, which are used as nuclear radiation detectors, are fabricated by two different methods, either by physical vapor deposition (PVD) or glued with a polymeric binder called also "particle in binder" (PIB). Both types of PVD or PIB detectors are deposited directly on TFT imagers and can be used for X-ray imaging. The present review will concentrate on PVD-poly-HgI₂ . However, the main review body will be a summary of the work performed by RTR, HU and Varian. Works by other groups will be mentioned briefly. The PVD process will be explained by reviewing XRD and SEM data. The charge transport properties of the PVD-polycrystalline HgI₂ detectors as they improved with R&D efforts will be shown. The response of these PVD detectors to ²⁴¹Am and ⁵⁷Co gamma rays and their X-ray imaging properties such as dark currents, sensitivity, and imaging resolution will be reviewed