Thermoelectric effect of silicon films prepared by aluminum-induced crystallization

Aluminum-induced crystallized silicon films were prepared on glass substrates by magnetron sputtering. Aluminum was added in the silicon films intermittently by the regular pulse sputtering of an aluminum target. The amount of aluminum in the silicon films can be controlled by regulating the aluminum sputtering power and the sputtering time of the undoped silicon layer; thus, the Seebeck coefficient and electrical resistivity of the polycrystalline silicon films can be adjusted. It is found that, when the sputtering power ratio of aluminum to silicon is 16%, both the Seebeck coefficient and the electrical resistivity decrease with the increasing amount of aluminum as expected; the Seebeck coefficient and the electrical resistivity at room temperature are 0.185-0.285 mV/K and 0.30-2.4 Ω·cm, respectively. By reducing the sputtering power ratio to 7%, however, the Seebeck coefficient does not change much, though the electrical resistivity still decreases with the amount of aluminum increasing; the Seebeck coefficient and electrical resistivity at room temperature are 0.219-0.263 mV/K and 0.26-0.80 Ω·cm, respectively.