Comparative Analysis of Multilayer Lead Oxide-Based X-ray Detector Prototypes

Abstract

Lead oxide (PbO) photoconductors are proposed as X-ray-to-charge transducers for the next generation of direct conversion digital X-ray detectors. Optimized PbO-based detectors have potential for utilization in high-energy and dynamic applications of medical X-ray imaging. Two polymorphs of PbO have been considered so far for imaging applications: polycrystalline lead oxide (poly-PbO) and amorphous lead oxide (a-PbO). Here, we provide the comparative analysis of two PbO-based single-pixel X-ray detector prototypes: one prototype employs only a layer of a-PbO as the photoconductor while the other has a combination of a-PbO and poly-PbO, forming a photoconductive bilayer structure of the same overall thickness as in the first prototype. We characterize the performance of these prototypes in terms of electron–hole creation energy (W±) and signal lag—major properties that define a material’s suitability for low-dose real-time imaging. The results demonstrate that both X-ray photoconductive structures have an adequate temporal response suitable for real-time X-ray imaging, combined with high intrinsic sensitivity. These results are discussed in the context of structural and morphological properties of PbO to better understand the preparation–fabrication–property relationships of this material.

Neutron Irradiation Effects on Boron Nitride-Based Ceramics for Use in X-ray Detection

“…Currently, the direct conversion of X-ray to electrical signal of commercial detectors is mainly based on amorphous selenium (α-Se) and cadmium zinc telluride (CZT). Other materials with high atomic numbers have also shown great potential for X-ray detection and imaging, such as CdTe, − lead oxide, polycrystalline HgI 2 , − and metal halide perovskites. − However, most of the current X-ray detection materials are still suffering from the poor stability, particularly under intense ionizing irradiation. It could be mainly due to the high attenuation coefficient of these dense materials with “heavy” atoms, and the incident high energy photons could be easily intercepted and have a great potential to generate large density of defects .…”