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.