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Abstract: We report the growth of (Cu C)Ba2Ca( n −1)Cu n O y (n=1–4) superconducting thin films by the molecular beam epitaxy method. The film was c-axis oriented for n=1, and was changed to a-axis oriented with 90° domains for n=2–4. All the films exhibited superconductivity and their T c''s were T c(on)=35K and T c(zero)=18K for n=1, T c(on)=80K and T c(zero)=52K for n=2, T c(on)=85K and T c(zero)=42K for n=3, and T c(on)=105K and T c(zero)=53K for n=4. [Copyright &y& Elsevier]

Abstract: β-FeSi2 film on Si(001) substrate was prepared by molecular beam epitaxy method using an Fe source. The crystallographic orientation of β-FeSi2 film on Si(001) substrate was characterized by using X-ray diffraction. Using scanning electron microscopy, surface morphology and film thickness of samples were observed and estimated, respectively. The mobility of β-FeS2 film on Si(001) substrate were also characterized by Hall measurement at room temperature. A part of the enhancement of figure of merit was evaluated as the functions of mobility and crystallographic orientation of samples. [Copyright &y& Elsevier]

Abstract: The effect of Se/(Ga+In) ratio, expressed as Se/III, on the electrical, optical and structural properties of Cu(In,Ga)Se2, abbreviated as CIGS, thin film and on the solar cell performance was studied. CIGS films with various Se/III ratios were grown by the molecular beam epitaxy (MBE) process. With decreasing Se/III ratio, the resistivity of CIGS film was found to be increased and majority carrier hole concentration was decreased. This is probably due to the formation of Se-vacancy and/or vacancy complex. Again, the band-gap energy of CIGS film increased and the Cu content in the bulk of the film decreased with decreasing Se/III ratio despite the Ga/III ratio in the film remained almost unchanged. These results may suggest the formation of anti-site defects such as InCu in CIGS. Solar cell performance degraded with decreasing Se/III ratio in CIGS absorber layer and the cause of the degradation was discussed. [Copyright &y& Elsevier]