PURPOSE: To improve the photoelectric conversion efficiency by a method where in the current of Si-H coupling of one silicon atom with two hydrogen atoms in the photoincidence side region in a photoactive layer is made higher than that in the other region.
CONSTITUTION: A semiconductor film 3 is composed of a P type layer 3P com prising hydrogenated amorphous silicon carbide (α-Sic:H); a photoactive layer 31 comprising a photoelectric conversing non-doped hydrogenated amorphous silicon (α-Si:H) producing photocarrier by photoincidence and an N type layer 3N comprising α-Si:H to form a PIN junction from a photodetector surface electrode 2 side as the photoincidence side in parallel with the film surface. The photoactive layer 31 comprising undoped α-Si:H photoelectric conversion positioned on the photoincidence side (i.e. the P type layer 3P side) is composed of an I 1 type layer 3I 1 in higher amount of Si-H 2 coupling of one silicon atom with two hydrogen atoms and an I 2 type layer 3I 2 in low amount of Si-H 2 coupling. Through these procedures, the photoelectric conversion efficiency can be improved.