Construction and characterization of an amorphous silicon flat-panel detector based on ion-shower doping process

In this paper, we introduce a new 36×43 cm2 amorphous silicon flat-panel detector for digital radiography. A prototype flat-panel detector was fabricated using a p–i–n photodiode/thin-film transistor (TFT) array. The main difference of this flat panel detector to the similar general flat-panel detectors is p–i–n photodiode fabrication method. The p-layer of diode is formed using an ion shower doping method instead of the conventional PECVD method to increase the quality of array. The diode shows a leakage current of 2 pA/mm2 at −5 V and dark current uniformity of the detector is 2.5%. The modulation transfer function (MTF) of the detector is 0.41 at 2 lp/mm.