Advanced III-V Multijunction Solar Cells Fabricated by Semiconductor Wafer Bonding

In recent years, the concept of wafer bonding has attracted significant attention since this approach allows direct integration of lattice-mismatched hetero-structure devices grown on different substrates by eliminating the major limitations of lattice matching requirements. The wafer bonding approach is particularly attractive for III-V based device structures since elimination of the lattice matching constraints allows novel device designs with otherwise impossible band-gap combinations, such as in multi-junction photo-voltaic devices with subcell band gaps tailored for optimum absorption of the solar spectrum.