Communications Satellite Corporation

Andrew Meulenberg, Jr

John H Reynolds

The surface recombination velocity at the back portion of a solar cell is reduced in a first embodiment by reducing the back surface metal contact area without increasing series resistance. The back surface is provided with a p.sup.+ layer deposited on the solar cell p layer in order to further reduce the surface recombination velocity and therefore the diffusion current generated in the back layer of the cell. The p.sup.+ layer is provided with an oxide coating. Micro holes are etched through the oxide layer, and a thin layer of metal is evaporated over the entire surface. In a second embodiment the surface recombination velocity at the back portion of the cell is reduced by depositing a thin non-conductive coating on the p.sup.+ layer. A selected metal coating is then deposited on the non-conductive coating to thereby form a Mott-Schottky barrier, the metal coating retarding the transport of minority carriers through the non-conductive coating without impeding the flow of majority carriers through the non-conductive coating. In a third embodiment, the surface recombination velocity is reduced by depositing a conductive oxide on the p.sup.+ layer, and a metal coating is further deposited on the conductive oxide coating. The conductive oxide coating reduces surface recombination at the interface of the p.sup.+ and conductive oxide layers, and provides majority carriers to the p.sup.+ layer.

Optimized back contact for solar cells

A dielectric film is provided with a metallic back layer for use as the outer layer in a multi layer 'thermal blanket' employed as part of the temperature control system for a spacecraft. The dielectric film is repeatedly punctured from the metallized side in order to produce a plurality of small holes, which collect a disproportionately large current from the plasma and adjacent charged surface. The rough edges of these holes also act to initiate frequent, small, field emissions, thereby preventing large surface potentials from building up in the presence of a 'hot' space plasma or electron beam environment.

Discharge suppressing dielectric film for use on spacecraft surfaces

A solar cell coverslide, oversize to protect the cell against damage from radiation, is modified to have an edge portion configured to bend light incident on said edge portion inwardly toward an underlying solar cell. An adhesive fillet may be formed between the undersurface of the overhanging portion of the coverslide and the top edge of the solar cell to facilitate further the transmission of light striking the configured edge portion into the solar cell.

Shaped edge solar cell coverslide

A solar cell is constructed such that the losses resulting from radiation damage are reduced without sacrificing efficiency in the unirradiated cell. This is done by using a first conductivity type junction on the front of a high resistivity cell and a second, opposite conductivity type junction on the back of the cell. The two junctions are separated by an intrinsic region, and the cell potential, which is normally reduced by using high resistivity substrate material, is instead raised by using the second junction. The cell includes a reflective back surface and a non-reflective front surface to further enhance light absorption within the active cell volume. The reflective back surface is formed by polishing the substrate. The non-reflective front surface is a multi-pyramidal or V-grooved surface formed by preferential etching of the substrate material. The front electrode is a fine geometry grid deposited over the front surface of the cell. An anti-reflection coating may additionally be provided over the front surface of the cell to further promote the non-reflective characteristics of that surface. Further, a cover slide may be cemented to the front surface of the cell.

Radiation hardened P-I-N and N-I-P solar cells

A cover slide for a solar cell comprises a plurality of converging lenses arranged to focus the incident light so that it does not fall on the grid lines of the front electrode of the solar cell.

Growing community of inventors

Gaithersburg, MD, United States of America

Andrew Meulenberg, Jr