An improved method of creating thermoelectric materials which have high electrical conductivity and low thermal conductivity is disclosed. In one embodiment, the thermoelectric material is made by depositing a porous film onto a substrate, introducing a dopant into the porous film and annealing the porous film to activate the dopant. In other embodiments, additional amounts of dopant may be introduced via subsequent ion implantations of dopant into the deposited porous film.