Toward Low-Cost 4-Terminal GaAs//Si Tandem Solar Cells

Kaitlyn T. Vansant, John Simon, John F. Geisz, Emily L. Warren, Kevin L. Schulte, Aaron J. Ptak, Michelle S. Young, Michael Rienäcker, Henning Schulte-Huxel, Robby Peibst, Adele C. Tamboli

Research output: Contribution to journalArticlepeer-review

17 Scopus Citations


Mechanically stacked III-V-on-Si (III-V//Si) tandem solar cells have demonstrated efficiencies beyond what can theoretically be achieved by single junction Si solar cells, but III-V costs are currently at least an order of magnitude higher than Si costs. Recent techno-economic analysis shows that costs could be substantially reduced by replacing traditional metalorganic vapor phase epitaxy (MOVPE) with a lower-cost III-V deposition technique, such as hydride vapor phase epitaxy (HVPE). This study analyzes the performance of an HVPE-grown GaAs top cell incorporated into a 4-terminal (4T) GaAs//Si tandem cell that achieved an efficiency of 29%, which is the highest solar cell efficiency fabricated without expensive deposition techniques such as MOVPE or MBE. We compare these results to an MOVPE-grown GaAs//Si tandem cell that has the same structure. Finally, we model optimizations to the HVPE-grown GaAs top cell and provide a near-term pathway to 31.4% efficiency with a low-cost III-V deposition technique.

Original languageAmerican English
Pages (from-to)2375-2380
Number of pages6
JournalACS Applied Energy Materials
Issue number4
StatePublished - 22 Apr 2019

Bibliographical note

Publisher Copyright:
© 2019 American Chemical Society.

NREL Publication Number

  • NREL/JA-5K00-73037


  • GaAs
  • HVPE
  • multijunction solar cells
  • photovoltaic cells
  • solar energy
  • tandems


Dive into the research topics of 'Toward Low-Cost 4-Terminal GaAs//Si Tandem Solar Cells'. Together they form a unique fingerprint.

Cite this