Abstract: A solar cell is constructed by coating an n-type conductivity semiconductor with a thin layer of bromine doped, polymeric sulfur-nitride, (SNBr.sub.0.4).sub.x. Metal deposits are provided on both materials for making electrical contact to the cell. In a preferred embodiment, the semiconductor is silicon. In a second preferred embodiment, the semiconductor is GaAs on an n.sup.+ -type conductivity GaAs substrate.

Abstract: Improved solar cells are provided by nano-structuring the solar cell active region to provide high optical absorption in a thin structure, thereby simultaneously providing high optical absorption and high carrier collection efficiency. Double-sided nano-structuring is considered, where both surfaces of the active region are nano-structured. In cases where the active region is disposed on a substrate, nano-voids are present between the substrate and the active region, as opposed to the active region being conformally disposed on the substrate. The presence of such nano-voids advantageously increases both optical and electrical confinement in the active region.

Abstract: A high efficiency triple-junction solar cell and method of manufacture therefor is provided wherein junctions are formed between different types of III-V semiconductor alloy materials, one alloy of which contains a combination of an effective amount of antimony (Sb) with gallium (Ga), indium (In), nitrogen (N, the nitride component) and arsenic (As) to form the dilute nitride semiconductor layer GaInNAsSb which has particularly favorable characteristics in a solar cell. In particular, the bandgap and lattice matching promote efficient solar energy conversion.

Abstract: Solar cells or photodetectors having one or more single-crystal shell layers conformally deposited on Ge nano-wires are provided. This approach can provide higher efficiency and/or reduced material cost compared to conventional planar approaches for multi-junction solar cells having the same thickness of active solar absorption materials. Shell layers deposited on the Ge nano-wires and including pn junctions can be grown such that they end up with single-crystal faceted tips, which can significantly improve optical collection efficiency and can improve the electron collection efficiency because of the high crystal quality.