Ultrathin GaAs space solar cell devices

This paper reports the continued development of ultrathin (6 μm) GaAs solar cells (UTCs) for application in space. Previously, the authors reported the development of 20×20 mm GaAs UTCs, made by the etchback or sacrificial substrate technique, with efficiencies up to 19.7% (1 sun AM0 aperture area). Further, they have reported the use of direct, adhesive-free coverglass bonding to enhance the strength of the device. The etch-back technique has been further developed, to larger area and multiple cells mounted on a single superstrate coverglass. The relative merits and disadvantages of three different techniques used to produce UTCs (CLEFT, PEEL, and sacrificial substrate) are discussed. Potential applications for UTCs are considered with the effects and requirements of the technology