The effect of light under electrical gate bias stresses on amorphous silicon thin film transistors as photo sensors

Abstract

We have investigated the charalerislics of amorphous silicon thin film transistors as photo sensors under electrical gate bias stresses with light illumination. We have analyzed the effect of light on the instability caused by electrical gate bias stresses. Threshold voltage (VTH) under the positive gate bias stress with light illumination was more increased than that under the positive gate bias stress without light illumination. VTH under the negative gate bias stress with light illumination was more decreased than that under the negative gate bias stress without light illumination. Sub-threshold slope (S.S.) under the positive gate bias stress with light illumination was more increased than that under the positive gate bias stress without light illumination. S.S. under the negative gate bias stress with light illumination was similar with thai under the negative gate bias stress without light illumination. These results of our experiments are due to the increase of carrier density in a channel region caused bv the light illumination.