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We demonstrate the direct heteroepitaxial growth of the quaternary semiconductor CuIn[sub (1-x)]Ga[sub x]S[sub 2] on Si(111) substrates by means of molecular-beam epitaxy. Using Rutherford backscattering, x-ray diffraction, transmission electron microscopy, and photoreflectance, samples of various Ga contents, x, were characterized in detail. Epitaxial growth was achieved in the whole compositional range and perfect lattice match between the epitaxial layer and substrate was obtained for x≈0.5. The epitaxial layers show the coexistence of bulk chalcopyrite and metastable CuAu-type cation ordering. Photoreflectance data reveal a linear increase of the fundamental band gap with increasing Ga content. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We demonstrate the direct heteroepitaxial growth of the ternary semiconductor CuGaS[sub 2] on Si(111) substrates by means of molecular beam epitaxy. X-ray diffraction data prove the epitaxial growth of the CuGaS[sub 2] films in the highly ordered chalcopyrite structure. Using photoluminescence, we are able to detect strong excitonic emissions up to room temperature, while photocurrent spectra reveal the A, B, and C valence-to-conduction-band transitions as they are typical for the tetragonal chalcopyrite structure. [ABSTRACT FROM AUTHOR]

Using three-source molecular beam epitaxy, we demonstrate the direct heteroepitaxial growth of the direct semiconductor CuInS[sub 2] on silicon (001) substrates. The pretreatment of the silicon wafers includes a high-temperature exposure to the sulphur beam which leads to an ideal (1×1) sulphur-terminated surface defining the starting condition for successful epitaxy. All stages of the growth process were controlled in situ using Auger electron spectroscopy and low energy electron diffraction. Furthermore, the epitaxial layers were characterized by means of x-ray diffraction methods and by transmission electron microscopy. It is shown that the CuInS[sub 2] epilayers grow with a tetragonal structure which is clearly distinct from chalcopyrite. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]