Motorola Corporation

Lawrence A Grenon

Michael G Coleman

Robert A Pryor

Fabio Restrepo

A method for electroplating a metallic layer onto the surface of a photovoltaic device absent any external electrical contacts to the surface. The photovoltaic device is placed in an electrolytic plating bath where it is illuminated with electromagnetic radiation to which the device is photovoltaically responsive. Plating from the electrolytic bath results from current flow generated in the device itself.

Electroplating method

A semiconductor cell for generating current in response to incident radiation, particularly solar energy, wherein a layer of material having charges is disposed over the PN current generating junction. The layer having charges possesses a net bound charge of the same polarity as the minority carriers associated with the underlying semiconductor material for aiding minority carrier flow across the PN junction and for minimizing recombination of those minority carriers at the surface of the semiconductor body.

Radiation responsive current generating cell and method of forming same

There is disclosed a monolithic light display comprising a matrix of light emitting diodes in an integral structure which is scannable to produce an alpha numeric character display. Each of the light emitting diodes is electrically isolated from each other diode in a supporting carrier, with the cathodes of the diodes connected in a series of groups by address lines and anodes connected in an orthagonal plurality of groups by bit lines or column lines. A strobing format logic address system is provided for lighting the individual diodes to emission for producing an alpha numeric character. There is also disclosed a method of making the foregoing which comprises moat etching a semiconductor substrate of a first conductivity to form a plurality of mesas in an orthagonal pattern desired for the ultimate alpha numeric display. A region of the opposite conductivity is then produced on the moat etched surface of the substrate by diffusing a suitable dopant therein. The PN junction is thereby formed following the contour of the moat etched surface. A layer of material is then deposted upon the diffused surface and a supporting carrier deposited over the first layer. If the first layer is of conductive material, the supporting carrier is required to be of dielectric material. If the first layer is of a dielectric material, the carrier may be either dielectric, heat conductive, or electrically conductive material. The original substrate is then removed by lapping, etching or polishing to leave only the mesas in a dielectrically isolated array. Suitable electrical connections are made to the individual diodes to complete the display.

Scannable light emitting diode array and method

There is disclosed a method of manufacturing the foregoing which comprises placing an epitaxial layer of a first conductivity type semiconductor material upon a substrate of semiconductor material having an intrinsic or semi insulating conductivity. Then channels are etched through the epitaxial layer to the semi insulating semiconductor substrate, thereby forming the epitaxial material into a plurality of parallel ribs or ridges. After coating the entire surface of the channels and the ridges with a dielectric layer, a conductive material is deposited over the substrate to fill the channels with the conductive material which may be either a metal or polycrystalline silicon doped to have sufficient conductivity. The surface of the substrate is then lapped to remove the conductive material and the dielectric material from the ridges to expose the first semiconductor material, and following diffusion of a dopant to convert the first semiconductor material to a second conductivity type material thereby forming a PN junction in each of the ridges in spaced locations therealong, suitable metallization is placed on the substrate to connect the first conductivity material to the conductive material in the channels to form column lines and metallization is placed on top a dielectric layer to connect the other conductivity material in a plurality of row lines.

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Phoenix, AZ, United States of America

Lawrence A Grenon