The Photosensitive Mechanism of Gap-Type Amorphous Silicon TFT

Gap-type amorphous silicon (a-Si) thin-film transistor (TFT) can provide high photo current in simple device structure, which makes it suitable for large-area-sensing applications. The reason why the photo current is much higher when the device is operated in the on-region than that in the off-region is not well studied. In this article, we propose the mechanism to explain this special phenomenon for the gap-type a-Si TFT. The feature of potential well is supported by TCAD simulation. The mechanism is further verified from the perspective of temperature effect and time response.