Comparative Study of HgI₂, PbI₂ and TlBr Films Aimed for Ionizing Radiation Detection in Medical Imaging

Abstract

Wide bandgap semiconductor films were obtained by spray pyrolysis, thermal evaporation and casting. These films were characterized under similar conditions in order to compare their structures, surface morphology and photocurrent properties. All films show either a crystalline or a polycrystalline structure. SEM pictures of sprayed films present holes and fissures and non-total covering of the substrate. The photoresponse was obtained for evaporated TlBr films, HgI 2 casted with polystyrene (PS) scaffold, sprayed and evaporated PbI 2 films. The photo to dark current ratio is discussed as well as the difference of photo to dark current at an electric field of 100 V/cm. The discussion also focuses on a future optimized material.

Evaluation of Relationship between Grain Morphology and Growth Temperature of HgI2 Poly-Films for Direct Conversion X-ray Imaging Detectors

“…Among a variety of detector materials, such as CdTe [1,2], PbI 2 [3][4][5], BiI 3 [6,7], and HgI 2 [8][9][10][11][12], HgI 2 turned out to be the superb one for direct and digital X-ray imaging for the last 15 years. Up to now, there is still a surge of interest in large area mercuric iodide (HgI 2 ) polycrystalline films in the application of digital radiographic detectors for medical diagnostic, scientific, and industrial applications on room-temperature X-rays [11,[13][14][15], especially the application of female breast lesion.…”