2.19 eV InGaP solar cells on GaP substrates

Stephanie Tomasulo, Joseph Faucher, Jordan R. Lang, Kevin Nay Yaung, Minjoo Larry Lee

Research output: Chapter in Book/Report/Conference proceedingConference contribution


We have grown, via molecular beam epitaxy (MBE), the first metamorphic In0.26Ga0.74P solar cells with a 2.19 eV direct bandgap on GaP to serve as the top cell in a multi-junction device. Calculations show that the incorporation of a 2.0-2.2 eV top cell into future 4-6 junction cells could enable efficiencies as high as 60%. GaAsxP1-x graded buffers enabled a moderate threading dislocation density of 6×10 6 cm-2 in the In0.26Ga0.74P solar cells. Open circuit voltages (Voc) as high as 1.42 V were observed under approximate AM1.5G illumination. Little work has been reported on the MBE growth of such highbandgap InyGa1-yP, and we believe that this Voc can be improved through systematic optimization of growth conditions. Although these devices were not optimized for current collection, we obtain an efficiency of 3.13%, surpassing that of the best GaP solar cells. Finally, as this composition is near the direct-indirect crossover point, we analyzed the low-energy cutoff of the external quantum efficiency spectrum and infer that our In0.26Ga0.74P cells are still in the direct regime.

Original languageEnglish (US)
Title of host publication39th IEEE Photovoltaic Specialists Conference, PVSC 2013
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages5
ISBN (Print)9781479932993
StatePublished - 2013
Externally publishedYes
Event39th IEEE Photovoltaic Specialists Conference, PVSC 2013 - Tampa, FL, United States
Duration: Jun 16 2013Jun 21 2013

Publication series

NameConference Record of the IEEE Photovoltaic Specialists Conference
ISSN (Print)0160-8371


Other39th IEEE Photovoltaic Specialists Conference, PVSC 2013
Country/TerritoryUnited States
CityTampa, FL


  • InGaP
  • Metamorphic
  • Molecular beam epitaxy
  • Wide-bandgap

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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