New High Resolution, Large Area Detector for Synchrotron Applications

Synchrotron radiation is a powerful tool for measuring structural properties of materials. Important applications of higher energy synchrotron X-rays include measurement of strain and material evolution during processing, studies of composite materials and studies of layered systems. Detector requirements for these applications include large area, high sensitivity, wide dynamic range, high spatial resolution and fast response. None of the existing detectors meet all of these requirements. We propose to develop a direct detection imager consisting of a compound semiconductor layer coupled to an amorphous silicon thin film transistor array. This detector promises to have higher sensitivity and higher spatial resolution than indirect detectors currently in use. In addition, a low-cost method that can easily be scaled to large areas will be employed to couple the semiconductor layer to the read out array. Prototype imaging detectors based on a compound semiconductor layer coupled to an amorphous silicon thin film transistor array were developed. Film deposition parameters were investigated. The detectors exhibited high sensitivity and high spatial resolution as predicted. Purification of the semiconductor material will be a focus of the Phase II work. Scale up of semiconductor film area and increase in uniformity will also be addressed. Imaging detectors will be characterized at a synchrotron facility. Commercial Applications and Other Benefits: In addition to the synchrotron applications mentioned above, a high resolution, large area detector would have important applications in X-ray diffraction and medical imaging including breast tomosynthesis and portal imaging.