Thermoelectric effect of silicon films prepared by aluminum-induced crystallization

Abstract

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.

Keywords

polycrystalline materials / thin films / silicon / thermoelectric effects / Seebeck effect / electrical resistivity / magnetron sputtering

References

[1] Lan Y.C., Minnich A.J., Chen G., Ren Z.F. Enhancement of thermoelectric figure-of-merit by a bulk nanostructuring approach. Adv. Funct. Mater., 2010, 20(3): 357

[2] Bux S.K., Blair R.G., Gogna P.K., Lee H., Chen G., Dresselhaus M.S., Kaner P.B., Fleurial J.P. Nano-structured bulk silicon as an effective thermoelectric material. Adv. Funct. Mater., 2009, 19(15): 2445

[3] G.H. Zhu, H. Lee, Y.C. Lan, X.W. Wang, G. Joshi, D.Z. Wang, J. Yang, D. Vashaee, H. Guilbert, A. Pillitteri, M.S. Dresselhaus, G. Chen, and Z.F. Ren, Increased phonon scattering by nanograins and point defects in nanostructured silicon with a low concentration of germanium, Phys. Rev. Lett., 102(2009), No.19, art. No.196803.

[4] Hochbaum A.I., Chen R.K., Delgado R.D., Liang W.J., Garnett E.C., Najarian M., Majumdar A., Yang P.D. Enhanced thermoelectric performance of rough silicon nano-wires. Nature, 2008, 451, 163

[5] Boukai A.I., Bunimovich Y., Tahir-Kheli J., Yu J.K., Goddard W.A.III Heath J.R. Silicon nanowires as efficient thermoelectric materials. Nature, 2008, 451, 168

[6] Radnoczi G., Robertsson A., Hentzell H.T.G., Gong S.F., Hasan M.A. Al induced crystallization of a-Si. J. Appl. Phys, 1991, 69(9): 6394

[7] Wood C.E.C., Metze G., Berry J., Eastman L.F. Complex free-carrier profile synthesis by atomic-plane doping of MBE GaAs. J. Appl. Phys, 1980, 51(1): 383

[8] Hou Q.R., Zhao W., Chen Y.B., He Y.J. Preparation of n-type higher manganese silicide films by magnetron sputtering. Int. J. Mod. Phys. B, 2009, 23(16): 3331

[9] Hou Q.R., Zhao W., Chen Y.B., Liang D., Feng X., Zhang H.Y., He Y.J. Thermoelectric properties of p-type higher manganese silicide films prepared by solid phase reaction and reactive deposition. Phys. Status Solidi A, 2007, 204(10): 3429

[10] Hou Q.R., Zhao W., Chen Y.B., Liang D., Feng X., Zhang H.Y., He Y.J. Thermoelectric properties of higher manganese silicide films with addition of chromium. Appl. Phys. A, 2007, 86(3): 385

[11] Dimova-Malinovska D., Angelov O., Sendova-Vassileva M., Kamenova M., Pivin J.C. Polycrystalline silicon thin films on glass substrate. Thin Solid Films, 2004, 451–452, 303

[12] Hou Q.R., Gu B.F., Chen Y.B. Seebeck effect of nano-scale p-type silicon films above room temperature. Mod. Phys. Lett. B, 2010, 24, 2457

[13] Liu E.K., Zhu B.S., Liu J.S. Semiconductor Physics, 1997 4th ed. Beijing, National Defense Industrial Press, 292.

[14] Seto J.Y.W. The electrical properties of polycrystalline silicon films. J. Appl. Phys., 1975, 46(12): 5247

[15] Nast O., Brehme S., Neuhaus D.H., Wenham S.R. Polycrystalline silicon thin films on glass by aluminum-induced crystallization. IEEE Trans. Electron. Devices, 1999, 46(10): 2062

[16] Pereira L., Águas H., Martins R.M.S., Vilarinho P., Fortunato E., Martins R. Polycrystalline silicon obtained by metal induced crystallization using different metals. Thin Solid Films, 2004, 451–452, 334