Abstract: A ZnO buffer layer having an electric conductivity of 1×10?9 S/cm or lower or alternatively a ZnO buffer layer having a diffraction peak of a crystal face other than (002) and (004) in X-ray diffraction is formed on a substrate by sputtering. A ZnO semiconductor layer is formed on the ZnO buffer layer. The ZnO semiconductor layer is formed under the condition that the flow rate ratio of an oxygen gas in a sputtering gas is lower than that in the formation of the ZnO buffer layer.

Abstract: A ZnO buffer layer having an electric conductivity of 1×10−9 S/cm or lower or alternatively a ZnO buffer layer having a diffraction peak of a crystal face other than (002) and (004) in X-ray diffraction is formed on a substrate by sputtering. A ZnO semiconductor layer is formed on the ZnO buffer layer. The ZnO semiconductor layer is formed under the condition that the flow rate ratio of an oxygen gas in a sputtering gas is lower than that in the formation of the ZnO buffer layer.

Abstract: This invention provides a photovoltaic device including an n-type microcrystalline Si layer, an i-type microcrystalline SiGe layer, and a p-type microcrystalline Si layer laminated on a substrate and using a thin microcrystalline silicon based semiconductor layer as a photoactive layer. The i-type microcrystalline SiGe layer is a microcrystalline SiGe layer which a Ge composition ratio is 20-40 at. %, a signal intensity of a Ge—Ge bond is 30-60% of a signal intensity of a Si—Si bond observed by the Raman spectroscopy, and a signal intensity of a Si—Ge bond is between those of the above two signal intensities.

Abstract: This invention provides a photovoltaic device including an n-type microcrystalline Si layer, an i-type microcrystalline SiGe layer, and a p-type microcrystalline Si layer laminated on a substrate and using a thin microcrystalline silicon based semiconductor layer as a photoactive layer. The i-type microcrystalline SiGe layer is a microcrystalline SiGe layer which a Ge composition ratio is 20-40 at. %, a signal intensity of a Ge—Ge bond is 30-60% of a signal intensity of a Si—Si bond observed by the Raman spectroscopy, and a signal intensity of a Si—Ge bond is between those of the above two signal intensities.

Abstract: An amorphous silicon germanium thin film is disclosed which contains hydrogen and germanium in concentrations of 5-10 atomic percent and 40-55 atomic percent, respectively for exhibiting the optical gap in the range of 1.30-1.40 eV. Also disclosed is a photovoltaic element incorporating the amorphous silicon germanium thin film.