NOVELTY - A photoelectric conversion device comprises: first electrode (110); light-transmitting semiconductor layer (130) over first electrode; first silicon semiconductor layer (140) over light-transmitting semiconductor layer; second silicon semiconductor layer (150) over first silicon semiconductor layer; and second electrode (120) over second silicon semiconductor layer, where light-transmitting semiconductor layer includes organic compound and inorganic compound.    USE - As photoelectric conversion device (claimed) e.g. solar cell.    ADVANTAGE - The photoelectric conversion device has small amount of light loss due to light absorption in window layer and high light efficiency. In device such as solar cell in which silicon oxide is used for p-layer serving as window layer, light loss due to light absorption in window layer is reduced, leading to increase in rate of light which reaches light absorption layer. However, in silicon oxide having larger band gap than silicon, resistance is not sufficiently reduced. Thus loss of current due to resistance is problem. In addition, field-effect photoelectric conversion device has many technical difficulties e.g. although rate of light which reaches i-layer is increased, relatively high voltage is needed for formation of inversion layer. Accordingly, commercialization has not been achieved. The photoelectric conversion device includes window layer that is formed using organic compound and inorganic compound and has high passivation effect on silicon surface. The light-transmitting semiconductor layer of the device is formed using organic compound and inorganic compound; where high hole-transport material is used as organic compound, and transition metal oxide having electron-accepting property is used as inorganic compound. The composite material formed has high transmittance of light in wide wavelength range from visible light region to infrared region. The composite material is stable, and silicon oxide is not generated at interface between silicon layer and composite material. Thus, defects at interface can be reduced, resulting in improvement in lifetime of carriers. When the light-transmitting semiconductor layer is used for window layer of photoelectric conversion device, light loss caused by light absorption in window layer is reduced, and electric characteristics of photoelectric conversion device can be improved. In addition, composite material has extremely high passivation effect on silicon surface. Accordingly, photoelectric conversion efficiency of photoelectric conversion device can be improved. Further, in device, when light enters the top cell through first electrode from substrate side, in first silicon semiconductor layer, light which is mainly in visible light region or on shorter wavelength side than visible light region is converted into electric energy. Then, in third silicon semiconductor layer, light which is mainly on longer wavelength side than visible light region and has passed through top cell is converted into electric energy. Therefore, light with wide wavelength range can be efficiently used, and conversion efficiency of photoelectric conversion device can be improved.    DETAILED DESCRIPTION - A photoelectric conversion device comprises: first electrode (110); light-transmitting semiconductor layer (130) over first electrode; first silicon semiconductor layer (140) over light-transmitting semiconductor layer; second silicon semiconductor layer (150) over first silicon semiconductor layer; and second electrode (120) over second silicon semiconductor layer, where light-transmitting semiconductor layer includes organic compound and inorganic compound. The first silicon semiconductor layer comprises material in non-single-crystal state, amorphous state, microcrystalline state, or polycrystalline state. The photoelectric conversion device comprises several first and second electrodes; and several isolation grooves are formed in stacked structure of light-transmitting semiconductor layer, first silicon semiconductor layer, and second silicon semiconductor layer, and each of the first electrodes is electrically connected to corresponding one of second electrode through corresponding at least one isolation groove. The photoelectric conversion device further comprises second light-transmitting semiconductor layer over second silicon semiconductor layer; third silicon semiconductor layer over second light-transmitting semiconductor layer; fourth silicon semiconductor layer over third silicon semiconductor layer; and second electrode over fourth silicon semiconductor layer, where each of first and second light-transmitting semiconductor layers includes organic compound and inorganic compound. The first and second light-transmitting semiconductor layers have p-type conductivity, first and third silicon semiconductor layers have i-type conductivity, and second and fourth silicon semiconductor layers have n-type conductivity. The first silicon semiconductor layer is amorphous, and third silicon semiconductor layer is microcrystalline or polycrystalline. The inorganic compound is oxide of metal belonging to Group 4 to Group 8 in periodic table. The photoelectric conversion device is formed on substrate (100) made from glass, or resin.    DESCRIPTION OF DRAWING(S) - The figure shows cross-sectional view of Photoelectric conversion device during a process of manufacturing the photoelectric conversion device.    Substrate (100)    First electrode (110)    Second electrode (120)    Light-transmitting semiconductor layer (130)    First silicon semiconductor layer (140)    Second silicon semiconductor layer (150)