HgI/sub 2/ polycrystalline films for digital X-ray imagers

• Published in: 2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149) Vol. 1; p. 8/12 vol.1
• Main Authors: Iwanczyk, J.S., Patt, B.E., Tull, C.R., MacDonald, L.R., Skinner, N., Fornaro, L.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2000
• Subjects: Amorphous silicon; Ionizing radiation; Semiconductor films; Semiconductor thin films; Sensor arrays; Thick films; Thin film transistors; X-ray detection; X-ray detectors; X-ray imaging
• ISBN: 9780780365032; 0780365038
• ISSN: 1082-3654; 2577-0829
• DOI: 10.1109/NSSMIC.2000.949302

This paper describes recent results obtained with mercuric iodide (HgI/sub 2/) polycrystalline films that we have produced. The ultimate goal of this effort is to develop a new detector technology for digital X-ray imaging, based on HgI/sub 2/ polycrystalline films coupled to large area flat panel amorphous silicon, thin-film transistor-addressed readout arrays. We have employed two approaches for producing the polycrystalline films: 1) thermal evaporation (sublimation) and 2) deposition of films from various solutions. The 40-60 micron thick films were characterized with respect to their electrical properties and in response to ionizing radiation. The leakage current was about 40 pA/cm2 at the operating bias voltages of /spl sim/50 V. Signals from the HgI/sub 2/ polycrystalline detectors, in response to ionizing radiation, compare favorably to the best published results for all high Z polycrystalline films grown elsewhere, including TlBr, PbI/sub 2/ and HgI/sub 2/.