Direct glassed and ultrathin GaAs cells

Solar cells can be attached to their protective cover-glass without any flexible adhesive. The devices then potentially have the advantages of higher ruggedness, lower mass and increased radiation hardness in high radiation environments. This paper describes the development of direct glassed (DG) GaAs solar cells, ultrathin cells (UTCs), and direct glassed ultrathin cells (DG-UTCs), for first in-orbit testing on the STRV solar cell flight experiment. To date, 4 cm/sup 2/ UTCs bonded with conventional DC93-500 have been demonstrated with 1 sun AM0 (25/spl deg/C) efficiencies of up to 19.7%. Thick (280 /spl mu/m) DG cells with efficiencies up to 16.3%, and 10 /spl mu/m DG-UTCs of up to 17.8% have been realised. The trials have indicated several approaches to improve UTCs to avoid any performance penalty, at a moderate increase in cost over conventional unthinned cells.