Evaluation of photoconductivities in diode connections using n-ch, p-ch, and pin-ch poly-Si TFTs for photosensor application

We have evaluated photoconductivities in diode connections using n-ch, p-ch, and pin-ch poly-Si TFTs for photosensor application. It is found that the photoconductivities increase as the illuminance increases for all the TFTs, but they do not change so much as the applied voltage changes. Moreover, the photoconductivities are: p-ch TFT <; pin-ch TFT with the gate terminal to the p-type region <; n-ch TFT <; pin-ch TFT with the gate terminal to the n-type region. Therefore, the pin-ch TFT with the gate terminal to the n-type region is the most suitable for photosensor application.