X ‐ r ay Photoconductivity and Typical Large‐Area X ‐ r ay Photoconductors

Abstract

The flat-panel X-ray imagers (FPXIs) have revolutionized both diagnostic and therapeutic medical X-ray imaging by facilitating a clinical transition to digital radiography. These image sensors have two major parts: the detector where X-rays are absorbed and charge carriers are generated and collected and the peripheral electronics that scan and process the collected charge from the detector for display or other form of readable information. The imaging performance of FPXIs critically depends on the photoconductor material used in the X-ray detector. The X-ray interactions with the photoconductor material, electron and hole pair creation energy, and signal formation mechanisms in the photoconductive detectors are discussed here. This chapter discusses the effects of charge carrier transport properties on the imaging performances such as X-ray sensitivity, resolution, and detective quantum efficiency. The material, transport, and imaging detector properties of several potential photoconductors used in direct conversion X-ray image detectors are described and critically compared in this chapter.