NOVELTY - Oxide material comprises: a substrate (605); and a single-crystal epitaxial layer of an oxide composition disposed on a surface of the substrate, where a unit cell of a crystal structure of the oxide composition comprises a first layer comprising a plane of lithium cations and a second layer comprising many edge-sharing octahedral, and the first layer and the second layer of the unit cell are alternatingly stacked along one axis of the unit cell.    USE - The oxide material is useful: in semiconductor devices; for splitting water (all claimed); in devices comprising memristors (which can be used in concert with both analog and digital computers/memory devices), neuromorphic computing, photoelectrolytic-hydrogen-generator cells, solar cells, batteries, memory cells, transistors and devices e.g. battery storage solar cells and transistors with inherent memory; in photovoltaic or solar cell applications; and to fabricate solar cells for capturing and harnessing solar energy.    ADVANTAGE - The oxide material: yields low resistance devices capable of having large ranges of resistance, thus enabling stored resistance values to be large, which provides memory storage capabilities, charge storage abilities and also capabilities to program generic memristors to desired operational states based on application of bias charges; are photo-chemically stable in aqueous solutions; provides a transformative integrated photovoltaic/battery that is capable of storing its own energy in an internal battery without the need for additional materials or construction.    DETAILED DESCRIPTION - Oxide material comprises: a substrate (605); and a single-crystal epitaxial layer of an oxide composition disposed on a surface of the substrate, where the oxide composition is of formula (AB1O2), a unit cell of a crystal structure of the oxide composition comprises a first layer comprising a plane of lithium cations and a second layer comprising many edge-sharing octahedral having a B1 cation positioned in a center of each octahedron and an oxygen anion at each corner of each octahedron and the first layer and the second layer of the unit cell are alternatingly stacked along one axis of the unit cell.    A = Li cation;    B1 = cation comprising trivalent transition metal cations, trivalent lanthanide cations, trivalent actinide cations and/or trivalent-p-block cations; and    O = oxygen anion.    INDEPENDENT CLAIMS are also included for:    (1) fabricating the oxide material, comprising providing the substrate and growing the single-crystal epitaxial layer of the oxide composition on a surface of the substrate;    (2) a semiconductor device (I) comprising a first layer of a first variable resistance material defining a first surface, the first variable resistance material being programmable to be one of an n-type or a p-type material, a second layer of a second variable resistance material defining a second surface, the second variable resistance material being programmable to be one of an n-type or a p-type material, the first layer being disposed proximate the second layer with the first surface and the second surface and defining a boundary interface between the first and second layers, and an electrical charge source in electrical communication with the first and second layers to supply a charge for programming resistances for the first variable resistance material and the second variable resistance material;    (3) a semiconductor device (II) comprising a first electrode and a second electrode, a metal-oxide semiconductor region disposed in electrical communication with the first electrode and the second electrode, the metal-oxide semiconductor region comprising a first epitaxial metal layer doped at a first doped level, a second epitaxial metal layer doped at a second doped level and a third epitaxial metal layer doped at a third doped level, the first, second and third epitaxial layer being positioned proximate to each other to form a first boundary interface between the first and second epitaxial layer and a second boundary interface between the second and third epitaxial layer, where the first, second and third epitaxial layer comprises a material enabling ion movement across the first and second boundary interfaces to enable varying resistance of the metal-oxide-semiconductor region;    (4) a semiconductor device (III) comprising a crystalline substrate and many electrodes spaced apart from the crystalline substrate, an array of variable resistance pillars being disposed between the crystalline substrate and at least one of the electrodes and the array of variable resistance pillars each comprising at least two layers of epitaxial-metal-oxide semiconductor materials, the semiconductor materials comprises the metal oxide compositions enabling ion/dopant flux through the variable resistance pillars in response to an electric potential, and where the variable resistance pillars can retain a resistance value as a function of charge associated with the electric potential;    (5) a semiconductor device (IV) comprising a first layer of a first variable resistance material defining a first surface and a second surface opposed from the first surface, the first variable resistance material being programmable to be one of an n-type or a p-type material, the first layer comprising material to transport holes and electrons between the first surface and the second surface in response to electric potential and an electrical charge source in electrical communication with the first layer to supply the electric potential for programming resistances for the first variable resistance material;    (6) a semiconductor device (V) comprising a solar cell device capable of converting light energy into an electric potential, where the solar cell device comprises a crystalline-lithium based semiconductor material, the semiconductor material comprises lithium ions that flux in response to the electric potential to enable the semiconductor material to retain a charge based on movement of the lithium ions within the semiconductor material; and    (7) a method of splitting water, comprising providing the single crystal epitaxial film of a p-type oxide of formula (AB1O2), contacting at least a first portion of a surface of the p-type oxide film with water, impinging at least a second portion of a surface of the p-type oxide film with a photon to produce an electron and a hole, moving the electron and the hole to different portions of the first portion of the surface of the p-type oxide film, reacting the hole at the first portion of the surface of the p-type oxide film with the water to produce oxygen gas and reacting the electron at the first portion of the surface of the p-type oxide film with the water to produce hydrogen gas.    DESCRIPTION OF DRAWING(S) - The figure graphically illustrates a memristor device.    Memristor device (600)    Substrate (605)    Many rectangular-shaped cross bars (610A-F)    Cylindrical column (615A-L)    Dual top electrodes (620, 625)