High Voltage GaAs Solar Cell for Linear Concentrator Arrays

AstroPower proposes to develop a new high voltage solar cell for photovoltaic linear concentrator arrays based on our thin GaAs solar cell and epitaxial lateral overgrowth technologies and applying lateral segment interconnection techniques. This solar cell design has several advantages which make it ideal for space concentrator systems. These are high system voltage (10 to 500 volts per cell), reliable low-cost interconnections, design flexibility, costs are independent of array voltage, and low power loss from shorts, opens, and impact damage. The low system current results in minimal I2R losses while the device design allows for minimal shading and resistance losses. This concentrator solar cell will incorporate the benefits of light trapping by growing the device active layers over a low-cost, simple, PECVD deposited silicon/silicon dioxide Bragg reflector. The projected power density is 5 kW/m2 for an AM0 efficiency of 26% at 1 5X. This solar cell design is capable of meeting the high voltage requirement of electric propulsion systems, without the complex stringing required by conventional solar cell designs. The proposed technology meets the requirements of linear concentrator arrays being developed such as SCARLET for the New Millenium Program and future BMDO satellites, but can be applied to any concentrator system.