A display device may include photo sensors connected to a readout line. Each of the photo sensors may include: a light receiving element; a first sensor transistor configured to control current flowing to the readout line in response to a voltage of one electrode of the light receiving element; and a second sensor transistor electrically connected between the first sensor transistor and the readout line. The first sensor transistor may include a silicon semiconductor. The second sensor transistor may include an oxide semiconductor.