Ohmic InP/Si Direct Bonding for Multijunction Solar Cell Applications

Direct-bonded ohmic InP / Si heterostructures are realized for the fabrication of lattice-mismatched multijunction solar cells and replacement of compound semiconductor substrates with silicon substrates. We have examined the dependence of electrical conductivity on bonding temperature and doping polarity, and obtained ohmic InP/Si heterointerfaces. Moreover, we have fabricated InP solar cells on Si and verified their photovoltaic operation.