GaAsP solar cells on GaP/Si grown by molecular beam epitaxy

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

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

Abstract

We demonstrate metamorphic 1.73 eV GaAs0.72P0.28 solar cells grown by molecular beam epitaxy on high-quality GaP/Si templates and compare them to cells co-grown on bulk GaP. Cascading such a cell with a 1.1 eV Si junction in the substrate could enable a theoretical efficiency of 37% under the AM1.5G spectrum. Electron beam-induced current studies of our cells reveal a threading dislocation density (TDD) of ∼1×107 cm -2 for cells on GaP/Si, which is significantly lower than previous reports. We believe that the combination of a highly optimized GaP/Si starting substrate with a well-designed metamorphic buffer enables these relatively low TDDs. Open-circuit voltages as high as 1.10 V were obtained, leading to a bandgap-voltage offset of 0.63 V. This bandgap-voltage offset is also lower than in previous reports, in qualitative agreement with the observation of lower TDD. Direct comparison with cells on bulk GaP confirm the relation between TDD and bandgap-voltage offset, indicating that more investigations to further reduce TDD in GaAsP single-junction cells are required to fulfill the ultimate goal of dual-junction integration on Si.

Original languageEnglish (US)
Title of host publication39th IEEE Photovoltaic Specialists Conference, PVSC 2013
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages2100-2104
Number of pages5
ISBN (Print)9781479932993
DOIs
StatePublished - Jan 1 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

Other

Other39th IEEE Photovoltaic Specialists Conference, PVSC 2013
CountryUnited States
CityTampa, FL
Period6/16/136/21/13

Keywords

  • GaAsP
  • III-V on silicon
  • Metamorphic materials
  • Solar cell

ASJC Scopus subject areas

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

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