Progress in the science and technology of direct conversion a-Se X-ray sensors

The present paper provides a critical review and discussion of some of the recent advances in the science and technology of stabilized a-Se (alloyed with 0.2–0.5% As and doped with small amounts of Cl) based flat panel X-ray sensors. Although a-Se is now a well-established X-ray photoconductor used in flat panel direct conversion X-ray sensors that have produced excellent images, there are many scientific aspects of the work that have not been resolved. We identify and discuss several further experimental and theoretical studies that must be undertaken to advance the science of X-ray photoconductors to a point that the new knowledge can be incorporated into enhanced device design.