This disclosure provides systems, methods, and apparatus related to a hybrid photo-electrochemical and photo-voltaic cell. In one aspect, device includes a substrate comprising a semiconductor, a transparent conductor disposed on the second surface of the substrate, a photoanode disposed on the transparent conductor, an electrolyte in electrical communication with the photoanode, and an electrode in contact with the electrolyte. The substrate is doped with a first n-type dopant. A first area of a first surface of the substrate is heavily doped with a first p-type dopant. A second area of the first surface of the substrate is heavily doped with a second n-type dopant. The second surface of the substrate is heavily doped with a second p-type dopant. The electrode is in electrical contact with the second area. The first area is in electrical contact with the second area through an electrical load.