OPTICAL AND STRUCTURAL-PROPERTIES OF ZNSE GAAS INTERFACES/

The results of high resolution X-ray diffraction clearly show that the strain in the ZnSe films is inhomogeneous and depends only on the fil m thickness and not on the growth temperature in the range of 285-325 degrees C; a value of similar to 0.17 mu m is inferred for the critica l thickness of ZnSe on GaAs. The measurements of the spectral response of the heterostructures give a strong photocurrent due to the absorpt ion edges of both GaAs and ZnSe. However, in the case of the GaAs sign al a shift towards lower energies is observed with the increase of sub strate temperature, indicating local differences in the structure of t he interfacial region. The analysis of the intensities of the LMM Auge r transitions of Zn and Se indicates the formation of an interfacial l ayer with excess of Se, suggesting the formation of a pseudomorphic Ga 2Se3 compound mixed with ZnSe at the interfacial region.