title: Modeling the imaging performance of prototype organic x-ray imagers.
abstract: A unified Monte Carlo and cascaded systems model for the simulation of active-matrix flat-panel imagers is presented. With few input parameters, the model simulated the imaging performance of previously measured flat-panel imagers with reasonable accuracy. The model is used to predict the properties of conceptual flat-panel imagers based on organic semiconductors on plastic substrates. The model suggests that significant improvements in resolution and detective quantum efficiency could be achieved by operating such a detector in a back-side illuminated configuration, or by employing two imaging arrays arranged face-to-face. The effect of semiconductor properties on the conceptual imagers is investigated. According to the model, a photodiode quantum efficiency of 25% and dark current of less than 100 pA mm(-2) would be satisfactory for a prototype imager, while a competitive imager would require a photodiode quantum efficiency of 40-50% with a dark current of less than 10 pA mm(-2) to be quantum limited over the radiographic exposure range.
authors.affiliation: Department of Medical Physics and Bioengineering, University College London, London WCIE 6BT, United Kingdom. james.blakesley@physics.org
authors.forename: J C
authors.initials: JC
authors.lastname: Blakesley
authors.forename: R
authors.initials: R
authors.lastname: Speller
mesh_terms: D003198:Computer Simulation; D003952:Diagnostic Imaging; D009010:Monte Carlo Method; D055095:Optics and Photonics; D009930:Organic Chemicals / Q000737:chemistry*; D010969:Plastics / Q000737:chemistry; D012666:Semiconductors; D014965:X-Rays
chemical_list: D009930:Organic Chemicals; D010969:Plastics