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(2), 4) a finger width of the front metal grid of 3 mum; 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(2) land 53.6 A/cm(2) at 2000 suns) with a simultaneous series resistance of 3 mn cm(2).