Abstract: Solar cells, particularly GaAs/GaSb tandem solar cells, are mounted on a honeycomb light weight panel in optical alignment with solar energy concentrators mounted on a front panel side. The cells are mounted on metallized surfaces of the heat spreader that is attached to a panel wall rear panel side. A circuit carrier has conductors which are bonded to metallization islands that are on one side only of the heat spreader. The circuit carrier is adhered to the rear panel side.

Abstract: A thin film I-III-VI.sub.2 based solar cell having a first layer of copper indium gallium selenide, a second layer of cadmium zinc sulfide, a double layer of zinc oxide, and a metallization structure comprised of a layer of nickel covered by a layer of aluminum. An optional antireflective coating may be placed on said metallization structure. The cadmium zinc sulfide layer is deposited by means of an aqueous solution growth deposition process and may actually consist of two layers: a low zinc content layer and a high zinc content layer. Photovoltaic efficiencies of 12.5% at Air Mass 1.5 illumination conditions and 10.4% under AMO illumination can be achieved.