Improvement in pixel signal uniformity of polycrystalline mercuric iodide films for digital X-ray imaging

We investigated polycrystalline mercuric iodide (HgI2) that exhibits uniform pixel signals for its use in digital X-ray imaging. To fabricate thin polycrystalline HgI2 films, the particle-in-binder (PIB) method is used because it enables the fabrication of X-ray conversion films at a low temperature and a normal pressure. Moreover, it has a large-scale deposition capacity at a low cost. Although the thin layers fabricated by the PIB method have such advantages, they are chemically unstable and show poor reproducibility and nonuniform X-ray response. To solve these problems, in this study, additional physical and chemical treatments were performed along with the PIB method after taking the size confinement effect of photoconductive particles into consideration. Morphological and electrical properties were measured to investigate the effects of the physical and chemical treatments.