Abstract: This is an improvement to the AlGaAs/GaAs heteroface solar cell in that the photovoltaically active region is composed of AlGaAs of low Al composition (approximately 2% to 10%) and is bounded by the usual high Al content (approximately 90% or more) AlGaAs window on the cell top and a novel high Al content (more than about 90%) back barrier. The back barrier serves to significantly reduce minority carrier losses in the rear region by blocking the carriers from reaching the cell substrate region. The result is that both light generated current and cell voltage performance will be improved.

Abstract: Doping with one of the group Ia elements Li, Na or K near the heteroface junction produced P+ conductivity in the gallium arsenide and N+ conductivity in the germanium. The device can be used, for example, as a dual bandgap solar cell. The fabrication includes implanting the group Ia dopant in a Ge wafer. This dopant diffuses into the GaAs when it is subsequently deposited on the Ge.

Abstract: Doping with one of the Group Ia elements Li, Na or K near the heteroface junction produces P+ conductivity in the gallium arsenide and N+ conductivity in the germanium. The device can be used, for example, as a dual bandgap solar cell. The fabrication includes implanting the Group Ia dopant in a Ge wafer. This dopant diffuses into the GaAs when it is subsequently deposited on the Ge.

Abstract: A polycrystalline rod of silicon is refined by repeatedly passing it through a zone melt condition, then a dopant impurity is ion implanted in the polycrystalline rod and a seed crystal is attached. A final zone melt pass is then made converting the rod to single crystal structure and distributing the dopant.