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Photovoltaics

Space Products: cells

Spectrolab produces multijunction GaInP2/GaAs/Ge solar cells for space applications.  Our most recent products are three junction solar cells in which each sub-cell reacts to a different portion of the incident solar spectrum to maximize response, and then operate collectively in series to provide an overall efficiency of 26-30% (Beginning of Life) depending on the product.  These solar cells are tuned to optimize performance at End of Life by harmonizing each cell’s current output after exposure to a typical 15 year mission in geosynchronous orbit.


Spectrolab grows the solar cell’s individual layers onto 10cm2 diameter germanium substrates via a process called Metal Organic Vapor Phase Epitaxy.  Metallization is applied to both front and rear sides of the solar cells from which small metal strips - known as interconnects (see CICs) - can route power from one cell to another.  Anti-reflection coatings are also applied to maximize use of incident light.


Once this processing is completed, individual cells are cut from the germanium wafer with a diamond embedded saw, typically in either 27 or 60cm2.


All solar cells inspected for mechanical defects and electrically tested.  All solar cell products have completed extensive qualification testing for Leo and Geo environments.


Spectrolab utilizes state of the art semiconductor process control tools, such as Six Sigma and DoE, to minimize process variability and maximize product quality for flawless operation in the extreme space environment.

 

Data Sheets (pdf)

30.7% NeXt Triple Junction (XTJ) Prime Solar Cells
29.5% NeXt Triple Junction (XTJ) Solar Cells
28.3% Ultra Triple Junction (UTJ) Solar Cells
26.8% Improved Triple Junction (ITJ) Solar Cells