Case 15192

Si-based Parallel Multijunction Solar Cells for Solar Spectrum Splitting, High Efficiency Concentrating Photovoltaics

Keywords:

CMOS, concentrating photovoltaic, III-V substrates, Ge substrates, spectrum splitting

Applications:

Concentrated photovoltaic technology

Problem:

Traditional solar cells in concentrating systems use expensive III-V or Ge substrates, require complicated film growth techniques for lattice matching and forming tunnel junctions, and necessitate current matching that is difficult to optimize for varying weather conditions.

Technology:

This invention describes an integrated approach which splits the solar spectrum into different bands directed toward discrete solar cells with spectrally matched bandgaps. This allows cells to be optimized independently. For each discrete solar cell, a single crystalline thin film Ge cell can be grown on top of a Si substrate to be used as a virtual substrate, replacing the Ge substrate.

Advantages:
  • Cost-savings compared to other spectrum splitting approaches
  • CMOS compatible
  • No longer a need for lattice and current matching
  • Flexibility in material choice based on bandgap considerations
  • Easy mounting
  • Reduced optical loss compared to physically mounting individual cells on a common substrate

Inventors:
  • Professor Lionel Kimerling (Department of Material Sciences and Engineering, MIT)
  • Xing Sheng (Department of Material Sciences and Engineering, MIT)
  • Juejun HU (Department of Material Sciences and Engineering, MIT)
  • Jing Cheng (Department of Material Sciences and Engineering, MIT)
  • Jifeng Liu (Department of Material Sciences and Engineering, MIT)
  • Lirong Zeng (Department of Material Sciences and Engineering, MIT)
  • Brian Albert (Department of Material Sciences and Engineering, MIT)
  • Jurgen Michel (Department of Material Sciences and Engineering, MIT)
  • Anuradha Agarwal (Department of Material Sciences and Engineering, MIT)

Intellectual Property:

US Patent Application Number 13/651140, filed on October 12, 2012

PCT Patent Application Number PCT/US2012/060082, filed on October 12, 2012

Publications:

N/A

Last revised: April 30, 2013

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