Analysis of lead oxide (PbO) layers for direct conversion X-ray detection

Abstract

Lead oxide (PbO) is a candidate direct conversion material for medical X-ray applications. We produced various samples and detectors with thick PbO layers. X-ray performance data such as dark current, charge generation yield and temporal behavior were evaluated on small samples. The influence of the metal contacts was studied in detail. We also covered large a-Si thin-film transistor (TFT)-plates with PbO. Imaging results from a large detector with an active area of 18 cm /spl times/ 20 cm are presented. The detector has 960 /spl times/ 1080 pixels with a pixel pitch of 184 /spl mu/m. The modulation transfer function at the Nyquist frequency of 2.72 linepairs/mm is 50%. Finally, a full size X-ray image is presented.