PHOTODETECTOR AND DISTANCE MEASUREMENT APPARATUS

A photodetector according to an embodiment of the present disclosure includes a first substrate, a second substrate, a first electrode, and a second electrode. The first substrate has a first surface serving as a light receiving surface and a second surface opposed to the first surface, and has a plurality of pixels disposed in an arrayed manner. The first substrate includes a light receiving section provided for each of the pixels. The light receiving section generates, through photoelectric conversion, electric charge corresponding to the amount of received light. The second substrate is disposed on a side of the second surface of the first substrate, has a third surface directly opposed to the second surface, and also has a fourth surface opposed to the third surface. The second substrate has a band gap wider than a band gap of the first substrate. The second substrate includes a multiplication section provided for each of the pixels. The multiplication section applies avalanche multiplication to the electric charge generated at the light receiving section. The first electrode is provided at the first surface of the first substrate and is electrically coupled to the light receiving section. The second electrode is provided at the fourth surface of the second substrate and is electrically coupled to the multiplication section.