NOVELTY - A photovoltaic cell (604) has compliant substrate (609) having base layer of silicon having layer of perovskite oxide and layer of silicon oxide; first sub-cell monolithically stacked on the substrate and having junction of p-type layer of semiconductor material in face-to-face contact with n-type layer of semiconductor material; and terminals (610, 612) attached to the cell to conduct current from and into the cell.    USE - The invention is used for converting radiant energy into electrical current and voltage. It is used in photovoltaic device and light emitting device. (all claimed)    ADVANTAGE - The invention uses combinations of lattice matched semiconductor materials in multi-sub-cell photovoltaic cells. It provides novel connections between these cells.    DETAILED DESCRIPTION - The photovoltaic cell comprises compliant substrate having base layer of silicon having layer of perovskite oxide and layer of silicon oxide interposed there between, the silicon oxide layer providing interfacial stress relief to the overlying perovskite oxide layer, allowing the substrate to accommodate growth of semiconductor materials having lattice constant of 5.4-5.9 Angstrom ; first sub-cell monolithically stacked on the substrate and having junction of p-type layer of semiconductor material in face-to-face contact with n-type layer of semiconductor material, the first sub-cell having lattice constant accommodated by the substrate and predetermined first band-gap energy; and terminals attached to the cell to conduct current from and into the cell.    INDEPENDENT CLAIMS are also included for:    (1) a photovoltaic device for converting radiant energy into electrical energy comprising an array of photovoltaic cells having first and second sub-cells; first sub-cell string formed by serially interconnecting the second sub-cell from the array of photovoltaic cells to another first sub-cell from the array of cells; and second sub-cell string formed by serially interconnecting the second sub-cell from the array of cells to another second sub-cell from the array of cells, the first sub-cells in the first sub-cell string is adjusted to provide a first voltage and the number of cells in the second sub-cell string is adjusted to provide a second voltage; and    (2) a light emitting device for converting electrical energy into light comprising array of light emitting cells comprising the substrate, the first sub-cell, the second sub-cell, and a third sub-cell mechanically stacked on the second sub-cell and composed of the semiconductor material; the first sub-cell string; the second sub-cell string; and a third sub-cell string formed by serially interconnecting the third sub-cell from the array of light emitting cells to another third sub-cell from the array of cells.    DESCRIPTION OF DRAWING(S) - The figure is a perspective view of the photovoltaic device having individual photovoltaic cells interconnected in voltage matched strings of sub-cells.    Photovoltaic device (600)    sub-cell strings (601, 603)    Photovoltaic cell (604)    Isolation layer (606)    Interconnections (608)    Substrate (609)    Terminals (610, 612)