30% Efficient InGaP/GaAs/GaSb Cell-Interconnected-Circuits For Line-Focus Concentrator Arrays

Period of Performance: 03/23/2000 - 03/23/2002


Phase 2 SBIR

Recipient Firm

JX Crystals, Inc.
1105 12th Avenue NW, Suite A2
Issaquah, WA 98027
Principal Investigator


This proposal calls for demonstration of 30 percent efficient, lightweight, affordable cell-interconnected-circuits for line focus photovoltaic concentrator systems. This will be done by combining the InGaP/GaAs cell with the GaSb cell in a two-terminal triple-junction mechanical-stacked configuration. The proposed team has participated in the development of concentrator systems over the past ten years. JX Crystals Inc. developed tandem mechanically-stacked cells for solar concentrators for NASA, and produces the GaSb booster cells and linear circuits in quantity. Tecstar and Entech played key roles in the success of the concentrator module on Deep Space 1; here, Tecstar will supply the InGaP/GaAs top cells and Entech will supply lenses and assemble the mini-module. NASA Glenn will test the module at the end of the project. Building on the successful demonstration of 30 percent efficient stacked tandem cells in phase I, the team plans to fabricate improved circuits that can be fitted into the concentrator panels of the type used on the Deep Space 1 mission. Able Engineering assembled the arrays on Deep Space 1 and has endorsed the approach of using the two-terminal triple-junction mechanical-stacked cell-interconnected-circuits proposed here. Able looks forward to incorporating higher circuit performance into their commercial concentrator arrays. The size and weight of a satellite's solar array have a large and direct impact on launch cost, and the 30 percent efficiency demonstrated here translates into smaller solar arrays for given power requirements. Launch cost savings should induce both telecommunications and military customers, especially for arrays conforming to the proven concentrator design of Deep Space 1.