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Resonant photothermal bending spectroscopy (RPBS) at various measurement temperatures has been developed for estimating absorption coefficient (α) spectra of thin film semiconductors. The experimentally obtained sensitivity of RPBS was about ten times larger than nonresonant PBS. In vacuum, this technique has been applied to estimate the α spectrum of hydrogenated microcrystalline silicon (μc-Si:H) films at the measurement temperatures from 25 to 150 °C. It is demonstrated that the temperature coefficient of an indirect optical absorption at 1.2–1.8 eV caused by Si microcrystallite is almost the same as that of single crystalline silicon, and the temperature coefficient of below-gap absorption intensity is negative. The reason for the negative temperature coefficient and the energy level of the localized state resulting in the below gap absorption are discussed.

Factors influencing spot-weldability of steel to aluminium with an intermediate layer of aluminium clad steel: Dissimilar metal joining of steel to aluminium with intermediate layer (Report 2), Welding International, 10:12, 943-954, Summary: This paper deals with the resistance spot weldability of steel to aluminium alloy using an intermediate layer of aluminium clad steel. Five types of clad sheet with various steel/aluminium thickness ratios were produced by hot rolling. The mechanical properties of the clad sheet changed with the thickness ratio and ranged between those of steel and:those of aluminium sheet. The peel strength of the steel/aluminium interfaces was greater than 25 N/mm.Materials used in spot welding were 0.8 mm thick EDDQ steel sheet, three types of 1.0 mm thick aluminium alloy sheet and the clad sheet mentioned above. Spotweldability, including suitable welding current, nugget diameter, tensile shear strength and thickness of the intermetallic compound layer formed at the interface of the clad sheets, changed with the thickness ratio of the clad sheet. From these results, it was concluded that spotweldability was affected by the thickness ratio of the clad sheets.Spot-weldability was also affected by the alloying elements in the aluminium alloy sheet. Tensile shear strength and nugget diameter varied in various types of aluminium alloy sheet.

Modeling of the mechanical response of single crystalline silicon to a sharp indenter is an essential step for the optimization of wafer manufacturing processes. In this paper, deformation of silicon during indenter loading and unloading was analyzed by the finite element method, and the changes of stress field and high-pressure phase distribution were dynamically simulated. We found that the deformation of silicon in nanoindentation can be simply characterized by two factors: one is the elastic strain of each high-pressure phase and the other is the equivalent elastic strain of each phase transformation. In loading, indentation energy is absorbed mostly by phase transformation, and accumulated as the elastic strain of the high-pressure phases. The distribution pattern of the high-pressure phases beneath the indenter is independent of the indentation load, and the depth of the phase-transformed region is approximately twice the indentation depth. In unloading, high-pressure phases except the β-Sn phase undergo reverse phase transformations. The β-Sn phase does not transform back to the diamond phase but changes to other non-equilibrium phases, which becomes the dominant reason for residual strain. During unloading, the non-equilibrium phase expands from the diamond phase region toward the indenter tip, while the boundary between the non-equilibrium phase and the diamond phase remains unchanged. The unloading mechanism is independent of the change in the maximum indentation load and the presence/absence of pop-out events.

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