According to an embodiment of the present disclosure, a photodetector device can include a substrate layer; a bottom contacting layer disposed over a surface of the substrate layer and having a first contacting region and a second contacting region, the bottom contacting layer providing a low resistance path between the first and second contacting regions; an insulating layer disposed over a surface of the bottom contacting layer; an intrinsic region disposed within the insulating layer, the intrinsic region in electrical contact with the first contacting region of the bottom contacting layer, the intrinsic region comprising a low band-gap material; a metal contact disposed within the insulating layer and in electrical contact with the second contacting region of the bottom contacting layer; an anode in electrical contact with the intrinsic region; and a cathode in electrical contact with the metal contact.