Light-sensing apparatuses, methods of driving the light-sensing apparatuses, and optical touch screen apparatuses including the light-sensing apparatuses

Abstract

Light-sensing apparatuses may include a light sensor transistor and a switching transistor in a light-sensing pixel, the transistors being oxide semiconductor transistors. In the light-sensing apparatus, the light sensor transistor and the switching transistor in the light-sensing pixel may be adjacently formed on one substrate, the switching transistor including a channel material that is relatively less light-sensitive than the light sensor transistor and is stable, and the light sensor transistor includes a channel material that is relatively light-sensitive. The light sensor transistor may include a transparent upper electrode on a surface of a channel, and a negative voltage may be applied to the transparent upper electrode, whereby a threshold voltage shift in a negative voltage direction may be prevented or reduced.