Signal readout in a-Si:H pixel detectors

Summary form only. Amorphous or poly-silicon thin-film technology can be used to make readout electronics for a-Si:H pixel detectors. A switch consisting of two a-Si:H p-i-n diodes was studied to read out signals from pixels for imaging of X-rays or gamma rays. A charge storage time of approximately 20 ms and a readout time of 0.7 mu s were achieved. In detection of single ionizing particles, a poly-silicon thin-film amplifier can be integrated to amplify the small signal at pixel level before readout. Prototype poly-silicon TFT (thin-film transistor) amplifiers were designed and fabricated. The measured gain-bandwidth product was approximately 300 MHz and the input equivalent noise charge was approximately 1000 electrons for a 1 mu s shaping time.<
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