NOVELTY - An integrated photovoltaic electrolysis cell (3) has photovoltaic component (1) and electrolysis component (2) integrated, through an interconnect design, into a single unit. The photovoltaic component has superstrate or substrate, transparent conducting front electrode, photovoltaic junctions, and electrically conductive back electrode. The electrolysis component has electrolyte, enclosure (40), reduction compartment, oxidation compartment, cathode (21), and anode (2).    USE - Used for conversion of sunlight into hydrogen generation by electrolysis.    ADVANTAGE - The invention is capable of generating enough voltage to split water. It does not need an external electrical bias for electrolysis. It is capable of surviving for extended use in the electrolyte. It can be fabricated using low-cost methods. It exhibits high potential for high conversion efficiency.    DETAILED DESCRIPTION - The integrated photovoltaic electrolysis (IPE) cell has photovoltaic component and electrolysis component integrated, through interconnect design, into single unit. The photovoltaic component is comprised of superstrate or substrate; transparent conducting front electrode; photovoltaic junction(s); and electrically conductive back electrode. The electrolysis component is comprised of electrolyte; enclosure that confines the electrolyte; reduction compartment for hydrogen generation; oxidation compartment for oxygen generation; cathode that is electrically connected to the negative electrode of the photovoltaic component, the cathode made of or coated with stable hydrogen generation catalyst material that has low hydrogen evolution overpotential and is electrochemically stable under reduction environment; anode that is electrically connected to the positive electrode of the photovoltaic component, the anode made of or coated with stable oxygen generation catalyst material that has low oxygen evolution overpotential and is electrochemically stable under oxidation environment; electrolyte inlet (41, 42) for the reduction and/or oxidation compartments; outlet for electrolyte and hydrogen in the reduction compartment; and outlet for electrolyte and oxygen in the oxidation compartment. An INDEPENDENT CLAIM is also included for a method for forming IPE cell, comprising integrating photovoltaic component and an electrolysis component, through an interconnect design, into single unit.    DESCRIPTION OF DRAWING(S) - The figure is a schematic perspective view of substrate-type IPE cell.    Photovoltaic component (1)    Electrolysis component (2)    IPE cell (3)    Porous support (17a)    Interconnection (18)    Grids (19)    Cathode (21)    Anode (22)    Enclosure (40)    Electrolyte inlets (41, 42)