Patent ID: 8049101

Claim:
A photovoltaic device comprising: a single-crystal substrate; a substantially intrinsic amorphous semiconductor thin-film layer containing hydrogen and provided on the single-crystal substrate; a doped amorphous semiconductor thin-film layer having a first and second region, the doped amorphous semiconductor thin-film layer containing hydrogen and provided on the intrinsic amorphous semiconductor thin-film layer; and a hydrogen-diffusion reducing area provided between the doped amorphous semiconductor thin-film layer and the intrinsic amorphous semiconductor thin-film layer, the hydrogen-diffusion reducing area reducing hydrogen diffusion from the intrinsic amorphous semiconductor thin-film layer to the doped amorphous semiconductor thin-film layer, wherein: the hydrogen-diffusion reducing area is an area formed in the vicinity of the interface between the doped amorphous semiconductor thin-film layer and the intrinsic amorphous semiconductor thin-film layer, the hydrogen-diffusion reducing area containing a higher concentration of hydrogen than that of the intrinsic amorphous semiconductor thin-film layer, and being doped with the same impurity as that for the doped amorphous semiconductor thin-film layer, the doped amorphous semiconductor thin-film layer includes a positive gradient of hydrogen concentration from the first region to the second region, the second region being closer to the intrinsic amorphous semiconductor thin-film layer than the first region, a concentration of the doped impurity in the hydrogen-diffusion reducing area is lower than that in the doped amorphous semiconductor thin-film layer, a concentration of the doped impurity in the first region of the doped amorphous semiconductor thin-film layer is higher than the concentration of the doped impurity in the second region of the doped amorphous semiconductor thin-film layer, and the concentration of hydrogen in the hydrogen-diffusion reducing area is more than that in the first region of the doped amorphous semiconductor thin-film layer and the intrinsic amorphous semiconductor thin-film layer.