PROJECT TITLE :

Direct-Conversion CMOS X-Ray Imager With Pixels

ABSTRACT:

We report a monolithic direct-conversion X-ray imager capable of detecting diagnostic level X-rays. The imager is made by combining a custom thirty two×32 CMOS four-transistor active pixel sensor (4T APS) array with an amorphous selenium photoconductive layer deposited on top of the array via a post processing step. A 4T APS with an express per-pixel integration capacitor is used to extend the pixel dynamic vary. Beneath dark conditions, an input-referred electronic noise of <;ninety electrons (rms) is estimated based mostly on measured noise information for a 40-ms integration time. The very initial X-ray images of copper and stainless-steel objects are included to demonstrate the performance of what is, to the best of our knowledge, a right away-conversion X-ray imager with the smallest pixel pitch reported to date.