Realization of axially defined GaInP/InP/InAsP triple-junction photovoltaic nanowires for high-performance solar cells

Abstract

III-V semiconductor-based planar multi-junction solar cells synthesized to match the solar spectrum, increase absorption, and reduce thermalization loss are today's world-record efficiency solar cells. Realizing similarly performing multi-junction III-V nanowire (NW) solar cells would require significantly less material and is more sustainable at lower cost than planar solar cells. The NW geometry allows expanding the range of compatible material combinations along the NW axis far beyond current multi-junction solar cells and enables promising applications in, for example, space power technology and smart windows. However, multi-junction NW photovoltaics have been hampered by the inability to electrically connect different materials in an axial geometry. We report the design and proof-of-principle demonstration of axially defined GaInP/InP/InAsP triple-junction photovoltaic NWs optimized for light absorption exhibiting an open-circuit voltage of up to 2.37 V. The open-circuit voltage is twice as large as previously reported for tandem-junction photovoltaic NWs and amounts to 94% of the sum of the respective single-junction NWs. Our findings pave the way for realizing the next generation of scalable, high-performance, and ultra-high power-to-weight ratio multi-junction, NW-based solar cells.