Hughes Aircraft Company

Spectrolab, Inc.

Kou-I Chang

David R Lillington

Bruce T Cavicchi

A monolithically integrated solar cell microarray includes an isolation layer or multiple isolation layers between a substrate and a solar cell layer, and a trench in the solar cell layer that exposes the isolation layer. Together the isolation layer and trench define solar cells that are spaced apart and electrically isolated on the monolithic substrate. The solar cells are scaled to provide a desired current. Base contacts and integral emitter contact/interconnects connect a number of the scaled solar cells in series to sum their voltages to supply a desired output voltage and current. The trench and integral emitter contact/interconnects are formed using photolithographic etching and liftoff processes, respectively, which are much quicker and less expensive than the conventional dicing and soldering processes.

Monolithically integrated solar cell microarray and fabrication method

A photocell (40) includes a photovoltaic or otherwise photosensitive layer structure (44) on which a passivation or window layer (52) of an environmentally sensitive material such as aluminum gallium arsenide (AlGaAs) and an antireflection (AR) coating (54) are formed. An electrically conductive cap layer (60) delineated in a front contact grid configuration sealingly extends through the AR coating (54) to the window layer (52). An ohmic metal contact (64) is evaporated over and seals the cap layer (60) and the contiguous areas of the AR coating (54). The contact grid interface at which the cap layer (60) contacts the window layer (52) is sealed by the AR coating (54) and the contact (64). The photocell (40) is fabricated by forming, delineating and etching the cap layer (60), forming the AR coating (54) and then forming the contact (64) by evaporation of metal.

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Yorba Linda, CA, United States of America

Kou-I Chang