Spectrolab, Inc.

The United States of America As Represented by the Administrator of the

United States of America As Represented by the Administrator of Nasa

Nick Mardesich

David R Lillington

Hans G Dill

George F Garlick

Sherwood D Mayall

John T Trauger

Timothy A McCann

Donald E Dunn

George A Fraschetti

The invention is a novel manufacturing method for making multi-junction solar cell circuits that addresses current problems associated with such circuits by allowing the formation of integral diodes in the cells and allows for a large number of circuits to readily be placed on a single silicon wafer substrate. The standard Ge wafer used as the base for multi-junction solar cells is replaced with a thinner layer of Ge or a II-V semiconductor material on a silicon/silicon dioxide substrate. This allows high-voltage cells with multiple multi-junction circuits to be manufactured on a single wafer, resulting in less array assembly mass and simplified power management.

Solar cell circuit and method for manufacturing solar cells

An alkali metal filter having a layer of metallic bismuth deposited onto the alkali metal is provided. The metallic bismuth acts to stabilize the surface of the alkali metal to prevent substantial surface migration from occurring on the alkali metal, which may degrade optical characteristics of the filter. To this end, a layer of metallic bismuth is deposited by vapor deposition over the alkali metal to a depth of approximately 5 to 10 .ANG.. A complete alkali metal filter is described along with a method for fabricating the alkali metal filter.

Alkali metal for ultraviolet band-pass filter

A method for providing deep impurity doped regions under the back contacts of a solar cell. In a semiconductor wafer with a p-n junction therein defining an n+ layer emitter and p-type layer bulk, a p+ layer is formed in the p-type layer under the back surface of the wafer. An oxide passivation layer is disposed over the back surface. Metal paste is screen printed onto the oxide layer in a predetermined pattern. The combination is heated to a temperature such that the metal paste will drive through the oxide layer and alloy with selected regions of p+ layer and p-type layer to a predetermined depth forming heavily doped p+ impurity regions. Metallization is applied onto the oxide layer making electrical contact with the heavily doped p+ impurity regions.

Drive through doping process for manufacturing low back surface

A gallium arsenide solar cell is disclosed having an aluminum gallium arsenide window layer in which fine metallic contact lines extend through the aluminum gallium arsenide window to electrically contact the emitter layer, and a plurality of metallic grid lines disposed on the window layer cross the contact lines, thereby making electrical contact to the metallic contact lines. A flat metallic strip extending along one of the edges of the solar cell electrically couples the grid lines to one another. Consequently, two separate metals can be used, one with good ohmic contact properties for the grid lines and another with good adhesion and current conducting properties for the current collecting bars. Additionally, the metallic contacts lines can be made very narrow to reduce the contact area to the emitter thereby reducing the recombination current in the emitter.

Solar cell having improved front surface metallization

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Simi Valley, CA, United States of America

Nick Mardesich