Tunnel Junction Development Using Hydride Vapor Phase Epitaxy

Journal Article · Wed Oct 18 00:00:00 EDT 2017 · IEEE Journal of Photovoltaics

DOI:https://doi.org/10.1109/JPHOTOV.2017.2756566· OSTI ID:1406185

Ptak, Aaron J. ^[1]; Simon, John D. ^[1]; Schulte, Kevin L. ^[1]; Jain, Nikhil ^[1]

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1. National Renewable Energy Laboratory (NREL), Golden, CO (United States)

We demonstrate for the first time III-V tunnel junctions grown using hydride vapor phase epitaxy (HVPE) with peak tunneling currents >8 A/cm², sufficient for operation of a multijunction device to several hundred suns of concentration. Multijunction solar cells rely on tunneling interconnects between subcells to enable series connection with minimal voltage loss, but tunnel junctions have never been shown using the HVPE growth method. HVPE has recently reemerged as a low-cost growth method for high-quality III-V materials and devices, including the growth of high-efficiency III-V solar cells. We previously showed single-junction GaAs solar cells with conversion efficiencies of ~24% with a path forward to equal or exceed the practical efficiency limits of crystalline Si. Moving to a multijunction device structure will allow for even higher efficiencies with minimal impact on cost, necessitating the development of tunnel interconnects. Here in this paper, we demonstrate the performance of both isolated HVPE-grown tunnel junctions, as well as single-junction GaAs solar cell structures with a tunnel junction incorporated into the contact region. We observe no degradation in device performance compared to a structure without the added junction.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1406185
• Report Number(s): NREL/JA-5J00-68632
• Journal Information: IEEE Journal of Photovoltaics, Vol. 8, Issue 1; ISSN 2156-3381
• Publisher: IEEE
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
gallium arsenide
hydride vapor phase epitaxy
photovoltaics
tunnel junctions