  We present a method for low temperature plasma-activated direct wafer bonding
of III-V materials to Si using a transparent, conductive indium zinc oxide
interlayer. The transparent, conductive oxide (TCO) layer provides excellent
optical transmission as well as electrical conduction, suggesting suitability
for Si/III-V hybrid devices including Si-based tandem solar cells. For bonding
temperatures ranging from 100$^{\circ}$C to 350$^{\circ}$C, Ohmic behavior is
observed in the sample stacks, with specific contact resistivity below 1
$\Omega$cm$^2$ for samples bonded at 200$^{\circ}$C. Optical absorption
measurements show minimal parasitic light absorption, which is limited by the
III-V interlayers necessary for Ohmic contact formation to TCOs. These results
are promising for Ga$_{0.5}$In$_{0.5}$P/Si tandem solar cells operating at one
sun or low concentration conditions.
