The direct bonding of an n-GaAs thin film onto the surface of epitaxia
l p-diamond is demonstrated. A rectifying characteristic is obtained f
or the present p-diamond/n-GaAs bonded junction system. Moreover, the
occurrence of the photovoltaic effect at the junction is observed unde
r illumination by an AlGaAs laser operated at 789nm. A diamond/GaAs pn
junction can be formed by direct bonding.