Wafer Bonding and Layer Transfer Processes for High Efficiency Solar Cells

    Research output: Contribution to conferencePaper


    A wafer-bonded four-junction cell design consisting of InGaAs, InGaAsP, GaAs, and Ga0.5In0.5P subcells that could reach one-sun AM0 efficiencies of 35.4% is described. The design relies on wafer-bonding and layer transfer for integration of non-lattice-matched subcells. Wafer bonding and layer transfer processes have shown promise in the fabrication of InP/Si epitaxial templates for growth of thebottom InGaAs and InGaAsP subcells on a Si support substrate. Subsequent wafer bonding and layer transfer of a thin Ge layer onto the lower subcell stack can serve as an epitaxial template for GaAs and Ga0.5In0.5P subcells. Additionally, wafer bonded Ge/Si substrates offer the possibility to improve the mechanical performance of existing triple-junction solar cell designs, while simultaneouslyreducing their cost. Present results indicate that optically active III/V compound semiconductors can be grown on both Ge/Si and InP/Si heterostructures. Current-voltage electrical characterization of the interfaces of these structures indicates that both InP/Si and Ge/Si interfaces have specific resistances lower than 0.1 ..omega..cm2 for heavily doped wafer bonded interfaces, enabling backsurface power extraction from the finished cell structure.
    Original languageAmerican English
    Number of pages4
    StatePublished - 2003
    EventNCPV and Solar Program Review Meeting - Denver, Colorado
    Duration: 24 Mar 200326 Mar 2003


    ConferenceNCPV and Solar Program Review Meeting
    CityDenver, Colorado

    NREL Publication Number

    • NREL/CP-520-35642


    • four-junction cells
    • high-efficiency solar cells
    • layer transfer
    • substrates
    • wafer bonding


    Dive into the research topics of 'Wafer Bonding and Layer Transfer Processes for High Efficiency Solar Cells'. Together they form a unique fingerprint.

    Cite this