This paper presents a study of an integrated infrared (IR) photo sensor for display application. We fabricated hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) and hydrogenated amorphous silicon germanium thin film transistor (a-SiGe:H TFT) which were bottom gate structure. We investigated the dependence of a-SiGe:H TFT characteristics on incident wavelengths. We proposed photo sensor which responded to wavelengths of IR region. Proposed pixel circuit of photo sensor was consists of switch TFT and photo TFT, and one capacitor. We developed integrated photo sensor circuit and investigated the performance of the proposed sensor circuit according to the input wavelengths. The developed photo sensor circuit with a- SiGe:H TFT was suitable for IR.
