We investigated the GaAs/ZnSe interface and the influence of the Ga2Se
3 formation at the GaAs/ZnSe interface on the relaxation of the ZnSe e
pilayer using reflection high-energy electron diffraction, atomic forc
e microscope, photoluminescence, and X-ray diffraction techniques. An
improvement of the surface roughness due to the cleaning of the GaAs s
ubstrate with hydrogen excited in a plasma source and a higher critica
l thickness of GaAs(001)/ZnSe due to the suppression of Ga2Se3 at the
surface was observed.