A GaAs solar cell with an efficiency of 26.2% at 1000 suns and 25.0% at 2000 suns

A GaAs solar cell without prismatic covers, with the highest efficiency known to the authors in the range of 1000-2000 suns for a single junction, is presented. Low temperature liquid phase epitaxy is used for its growth. In addition to improvements such as the achievement of a good quality material or a low contact resistance, this solar cell exhibits specific enhanced aspects. Among the most noticeable are: (1) an innovative design; (2) a double and gradual emitter layer; (3) a small size: 1 mm/sup 2/, (4) a finger width of the front metal grid of 3 /spl mu/m; and (5) a tailored ARC deposition based on a nondestructive and accurate AlGaAs window layer characterization. As a consequence, an efficiency of 26.2% at 1000 suns and 25.0% at 2000 suns AM1.5D (standard conditions) is achieved thanks mainly to a short-circuit current density at 1000 suns of 26.8 A/cm/sup 2/ (and 53.6 A/cm/sup 2/ at 2000 suns) with a simultaneous series resistance of 3 m/spl Omega//spl middot/cm/sup 2/.