The piezoelectric photo-thermal signals from hydrogenated microcrystalline silicon (μc-Si:H) films were measured and the effects of the deposition rate on the optical properties of these films were investigated. We found that the increase of the deposition rate results in (i) the decrease of optical absorption coefficient around 1.5eV (??), (ii), the blue shift of the critical band gap energy and (iii) the appearance of the localized states originated from a structural disorder. These results lead to a decrease of the conversion efficiency of the solar cells for high deposition rate sample. The usefulness of PPT method for investigating the optical properties of thin and transparent μc-Si:H film was demonstrated. (JJAP 2004)

　

(JJAP、USES, etc.）

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