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High Efficiency Lattice-Matched 4J Space Solar Cells on GaAs

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Original languageEnglish
Title of host publication2019 European Space Power Conference (ESPC)
ISBN (Electronic)978-1-7281-2126-0
ISBN (Print)978-1-7281-2127-7
Publication statusPublished - Oct 2019
Publication typeA4 Article in a conference publication
EventEuropean Space Power Conference -
Duration: 1 Jan 2000 → …


ConferenceEuropean Space Power Conference
Period1/01/00 → …


A lattice-matched four-junction solar cell on a GaAs substrate, for space applications, is demonstrated. The solar cell incorporates MBE grown GaInP, GaAs, GaInNAsSb and GaInNAsSb junctions with band-gaps of 1.9 eV, 1.4 eV, 1.2 eV and 0.9 eV, respectively. For AM0 illumination, the cell exhibited a maximum efficiency of 27%. For this performance, a high collection efficiency for the bottom cell is required. The high efficiency and current generation for the four-junction solar cell is primarily enabled by achieving a very low background doping level (~5×1014 cm-3) and high charge carrier lifetimes (2-4 ns) for the GaInNAsSb bottom junction. Achieving an efficiency of 33% is deemed possible by further reduction of reflection, shadowing and transmission losses.

Publication forum classification

Field of science, Statistics Finland