A Hydrogenated Amorphous Silicon Thin-Film Transistor Optical Pixel Sensor for Ameliorating Influences of Ambient Light and Reflected Light

Abstract

This paper proposes a hydrogenated amorphous silicon thin-film transistorbased (a-Si:H TFT) optical pixel sensor. The proposed optical sensor compensates for variations of ambient light using photo TFTs that incorporate with three primary color filters, and a designed active load is utilized to release the photocurrent from the noise of reflected light. Measurement results reveal that the proposed sensor suppresses the effect of ambient light within the intensity of 12 560 lux and does not react to a blue light with an intensity of 588 lux, proving that the proposed optical sensor remains highly reliable under heavy ambient light and avoids the interference of reflected light.