Investigation of AlInAsSb/GaSb tandem cells – A first step towards GaSb-based multi-junction solar cells

Abstract III-Sb semiconductors cover the whole 0.29–1.64 eV bandgap range, allowing us to grow several subcells of a multi-junction solar cell lattice-matched to GaSb. Among III-Sb alloys, AlInAsSb exhibits the broadest range of direct bandgaps, making it a promising material for photovoltaic applications. In this work, the behavior of two AlInAsSb/GaSb tandem photovoltaic cells is studied. Material characterization and physics-based 1D modeling are carried out to analyze and discuss performance of the cells. An efficiency of 5.2% is achieved under 1-sun illumination, limited by the AlInAsSb quaternary-alloy properties.