Quantitative evaluation of mercuric iodide and selenium for X-ray imaging device

Analog film/screen systems have been replaced with digital X-ray imaging devices using direct conversion materials. In this paper, mercuric iodide (HgI₂) and amorphous selenium (a-Se) films were deposited through the particle-in-binder (PIB) and physical vapor deposition (PVD) methods, respectively. Using the MCNP 4C code, the interaction of X-ray photons in HgI₂ and a-Se bulk, their transport, and transmitted energy spectrum of continuous X-ray, with total absorbed energy were simulated. Using I-V measurements, their electrical properties, such as leakage current, X-ray sensitivity, and signal-to-noise ratio (SNR), were investigated. The results of our study can be useful in the future design and optimization of direct active-matrix flat-panel detectors (AMFPD) for various digital X-ray imaging modalities.