A photovoltaic device, wherein a non-crystalline semiconductor layer of one conductivity type formed on a single crystal or a polycrystalline semiconductor substrate of the opposite conductivity type is annealed thereby to change the non-crystalline semiconductor to a polycrystalline semiconductor, with a pn junction plane formed therebetween. The depth of the junction plane is 500 .ANG. or less from the light incident surface of the polycrystallized semiconductor. Moreover, the light incidence surface can be made uneven by increasing the growth rate of the non-crystalline semiconductor.