Flexible and Large‐area X‐ray Detectors

Flat panel x-ray detectors for medical diagnostic applications were commercialized just before the turn of the millennium. This chapter describes basic operation principles of a flat panel detector and the different building blocks. It discusses novel semiconductor materials that can be used as sensing photodiodes. Flat panel digital x-ray detectors are usually classified as direct conversion or indirect conversion, depending on the process for converting the incident x-rays into charge. The chapter focuses on materials that can be processed from solutions over large area using low-temperature processes, making them attractive from a cost point of view for detectors on plastic as well as glass. It briefly introduces flexible thin-film transistor (TFT) technologies, guided by their requirements in x-ray detectors. Earlier prototypes on flexible TFT arrays for large-area imagers are discussed, followed by a more detailed description of a recent medical-grade detector. Finally, the chapter outlines directions for future research.