A semiconductor device including, on at least one surface of a crystalline semiconductor substrate, at least one first amorphous semiconductor region doped with a first type of conductivity. The semiconductor substrate includes, on the same at least one surface, at least one second amorphous semiconductor region doped with a second type of conductivity, opposite the first type of conductivity. The first amorphous semiconductor region, insulated for the second amorphous semiconductor region by at least ore dielectric region in the contact with the semiconductor substrate, and the second amorphous semiconductor region form an interdigitated structure.