Investigation of PbI₂ Film Fabricated by a New Sedimentation Method as an X-ray Conversion Material

Radiation detectors are currently fabricated by a screen-print method at room temperature. However, this method has many disadvantages in terms of thickness control and electron trapping. We fabricated polycrystalline PbI 2 films by a new sedimentation method and compared the results with those obtained by the existing screen-print (SP) method. We investigated the electrical and structural properties of the films. We fabricated 2 ×2 cm 2 sample films with a thickness of about 200 µm. A field emission scanning electron microscopy (FE-SEM) analysis showed that these films were of higher density than those fabricated by a conventional SP method. We also measured the photosensitivity and dark current of the films. The photosensitivity of the films fabricated by the new sedimentation method was 4.8 pC/(mR·mm 2 ), and the dark current was 2.2 pA/mm 2 at 1.0 V/µm. The linearity of the film ranged from 3 to 12 mAs, which is promising for diagnostic radiography.