X-ray imaging with semiconductor films

In this paper, a novel approach for developing a large area, high spatial resolution x-ray imaging detector is discussed. This approach integrates the flat panel amorphous silicon readout technology with the polycrystalline lead iodide photoconductive x-ray detection technology. This Pbl2 detector design is promising because it provides high x-ray stopping efficiency, high efficiency conversion of x-ray energy into electronic change, high signal amplitude due to efficient collection of these changes, and high spatial resolution due to electro-static focusing of these changes. We have designed and fabricated prototype 2' X 2' imagers with 200 micrometers pixels (256 X 256 elements) using this approach. The performance of these imagers is characterized by measuring their dark current, x-ray induced signal amplitude, spatial resolution, and uniformity of response. Some basic properties of lead iodide films are also evaluated and presented.