A disclosed photosensor includes: a first electrode layer including a reflection part having an inclination surface; a first semiconductor layer positioned on the first electrode layer; a second electrode layer positioned on the first semiconductor layer; and a first dielectric layer and a second dielectric layer sequentially positioned on the second electrode layer, wherein the first dielectric layer and the second dielectric layer have different dielectric constant values. Further, the disclosed display device includes a plurality of pixel areas positioned on a substrate, and a sensor unit formed in at least some pixel areas among the plurality of pixel areas.