Development of the GaAs solar cell for space application

To meet the requirements of space power use, the authors developed a new multiwafer LPE technique. This technique applied a squeezing multiwafer graphite boat, with 50 wafers (2.3/spl times/2.3 cm/sup 2/) or 20 wafers (2.3/spl times/ 4.3 cm/sup 2/) produced at each epitaxial growth. They focused on the control technique for the epitaxial layers' parameters. Experimental results demonstrated that epitaxial growth at low temperature could produce ideal GaAs solar cells with good repeatability. To date, the efficiencies of GaAs solar cells prepared by this technique have reached 18.6% (2/spl times/2 cm/sup 2/, AMO) and 18.39% (2/spl times/4 cm/sup 2/, AMO), respectively. Average efficiency of the cells prepared in a small lot is 17.5% (AMO), and all the samples were qualified in space environment simulation tests.