Sensitivity of a nanodoped polymer based X-ray image detector

Abstract

The X-ray sensitivity of direct conversion X-ray image detectors based on poly(triarylamine) (PTAA) doped with bismuth oxide (Bi2O3) nanoparticle is determined for mammography. Using COMSOL Multiphysics 5.0, the continuity equations are solved considering drift of charge carriers in the presence of deep traps. The recombination between drifting charge carriers and nonuniform electric field across the photoconductor layer is also considered. Poole-Frenkel mechanism has been considered for electric field dependent mobility of charge carriers. A very promising X-ray sensitivity of 1.3295µC/cm2R has been found at an applied electric field of 10V/µm. The calculated sensitivity has been compared with that of the commercially available amorphous selenium (a-Se) based direct conversion X-ray image detector.