Direct bonding of an n-GaAs thin film onto the surface of epitaxial p-
diamond has been attempted. Prior to bonding, the diamond and GaAs sur
faces were analyzed by X-ray photoelectron spectroscopy. A rectifying
characteristic was obtained for the p-diamond/n-GaAs bonded junction s
ystem. Moreover, the occurrence of a photovoltaic effect at the juncti
on was observed under illumination with a AlGaAs laser operated at 789
nm. Thus a Diamond-GaAs pn junction can be formed by direct bonding.