Rotating bending fatigue tests were carried out on the precipitation hardening stainless steels in order to clarify the fatigue properties through successive observation of crack initiation and its propagation behavior. The fatigue strength of precipitation hardening stainless steels was increased with aging, which was caused by the increase in both resistances for a crack initiation and its propagation. No effect, if any, of aging conditions on the fatigue life was observed, while the crack initiation and its propagation behavior was markedly influenced by aging condition. Both static strength and fatigue strength increase on both materials by the aging treatment, while the increase of the fatigue strength is smaller than the rise in the static strength.

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Rotating bending fatigue tests were carried out to investigate fatigue properties of high silicon stainless steel and SUS630 stainless steel, both of which were precipitation hardening stainless steel. The tests were performed at room temperature and elevated temperature of 400℃. Both static strength, fatigue strength increased on precipitation hardening stainless steel by the aging treatment. The high silicon stainless steel X material increased most on both static strength and fatigue strength among three kinds of steel. The fatigue strength at elevated temperature of 400℃ of the high silicon stainless steel X material was intensified further than solution heat treatment material of room temperature in all stress range. Although the initiation site of fracture was the surface of SUS630 stainless steel, it occurred in the specimen surface at high stress levels and the interior at low stress levels in the high silicon stainless steel X material.

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Structural, electrical and optical properties of non-doped and Sb-doped CuInS_2 thin films grown by single source thermal evaporation method were studied. The films were annealed from 100 to 500℃ in air after the evaporation. The x-ray diffraction spectra indicated that polycrystalline CuInS_2 films were successfully obtained by annealing above 200℃. This temperature was lower than that of non-doped films. The surface morphologies of the non-doped samples were investigated by scanning electron microscopy. The maximum grain size of the samples after annealing at 400℃ was above 500nm. Furthermore, we found that the Sb-doped films became close to stoichiometry in comparison with non-doped films. The Sb-doped samples annealed above 200℃ has bandgap energy of 1.43〜1.50eV.

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Electron nonradiative relaxation through the proton-irradiation-induced defects in CuInSe_2 solar cell material were investigated by using a new developed piezoelectric photothermal spectroscopy (PPTS). Among the observed three peaks at 1.01, 0.93 and 0.84eV, it was concluded that the peak at 0.84eV was due to the proton-irradiation-induced defect. This is because this peak appeared after irradiation with the proton energy of 0.38MeV andthe fluence of 1×10^14cm^<-2>. The peaks at 1.01 and 0.93eV were attributed to free band edge exciton and intrinsic defect level, respectively. Theintensities for the latter two peaks were not affected by the irradiation. Since the irradiation defect was clearly observed at room temperature, we concluded that the PPTS technique was a very sensitive tool to study the defect level in the irradiated semiconductor thin-film solar cell structures.

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