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Structural, Optical, and Electron Transport Qualities of Zinc-Stannate Thin Films

Published online by Cambridge University Press:  21 March 2011

David L. Young ,
Timothy J. Coutts  and
Don L. Williamson
David L. Young
Affiliation:
National Renewable Energy Laboratory, Golden, CO 80401, U.S.A.
Timothy J. Coutts
Affiliation:
National Renewable Energy Laboratory, Golden, CO 80401, U.S.A.
Don L. Williamson
Affiliation:
Colorado School of Mines, Golden, CO 80401, U.S.A.
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Abstract

Single-phase, spinel zinc stannate (ZTO = Zn2SnO4) thin films were grown by rf magnetron sputtering onto glass substrates. Uniaxially oriented films with resistivities of 10−2 -10−3 ωcm, mobilities of 16 - 26 cm2/V-s, and n-type carrier concentrations in the low 1019 cm−3 range were achieved. X-ray diffraction peak intensity studies established the films to be in the inverse spinel configuration. 119Sn Mössbauer studies identified two octahedral Sn sites, each with a unique quadrupole splitting, but with a common isomer shift consistent with Sn+4. A pronounced Burstein-Moss shift moved the optical bandgap from 3.35 eV to as high as 3.89 eV.

Density-of-states effective mass, relaxation time, mobility, Fermi energy level, and a scattering parameter were calculated from transport data. Effective-mass values increased with carrier concentration from 0.16 to 0.26 me as the Fermi energy increased from 0.2 to 0.9 eV above the conduction-band minimum. First-order nonparabolic conduction-band theory was applied to extrapolate a bottom-of-the-band effective mass of 0.15 me. Calculated scattering parameters and temperature-dependent transport measurements correlated well with ionized impurity scattering with screening by free electrons for highly degenerate films.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 666: Symposium F – Transport and Microstructural Phenomena , 2001 , F3.8
Copyright
Copyright © Materials Research Society 2001

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References

REFERENCES

1 Wu, X., Mulligan, W. P., and Coutts, T. J., Thin Solid Films 286, 274–276 (1995).Google Scholar
2 Enoki, H., Nakayama, T., and Echigoya, J., Phys. Stat. Sol. (a) 129, 181 (1992).Google Scholar
3 Wu, X., Coutts, T. J., and Mulligan, W. P., J. Vac. Sci. Technol. A 15 (3), 1057–1062 (1997).Google Scholar
4 Young, D. L., “Electron Transport in Zinc Stannate (Zn2SnO4) Thin Films,” Doctoral Thesis, The Colorado School of Mines, Physics Department (2000).Google Scholar
5 Wu, X., Sheldon, P., Mahathongdy, Y., Ribelin, R., Mason, A., Moutinho, H. R., and Coutts, T. J., “CdS/CdTe Thin-Film Solar Cell with a Zinc Stannate Buffer Layer,” presented at the National Center for Photovoltaics Program Review Meeting, Denver, CO (1998).Google Scholar
6 Wu, X., Ribelin, R., Dhere, R. G., Albin, D. S., Gessert, T. A., Asher, S., Levi, D. H., Mason, A., Moutinho, H. R., and Sheldon, P., Proceedings of the 28th IEEE Photovoltaic Specialists Conference (Anchorage, Alaska, September 17-22, 2000).Google Scholar
7 Williamson, D. L., Niesen, L., Weyer, G., Sielemann, R., and Langouche, G., “Mö ssbauer Spectroscopy,” in Hyperfine Interaction of Defects in Semiconductors, edited by Langouche, G. (Elsevier, Amsterdam, 1992) pp. 75.Google Scholar
8 Young, D. L., Coutts, T. J., and Kaydanov, V. I., Review of Scientific Instruments 71 (2), 462–466 (2000).Google Scholar
9 O'Neill, H. S. C. and Navrotsky, A., American Mineralogist 68, 181–194 (1983).Google Scholar
10 Williamson, D. L., Young, D. L., and Coutts, T. J., Submitted to J.A.P. (2001).Google Scholar
11 Burstein, L., Phys. Rev. 93, 632–633 (1954).Google Scholar
12 Moss, T. S., Proc. Phys. Soc. A. 382, 775–782 (1954).Google Scholar
13 Kolodziejczak, J. and Sosnowski, L., Acta Phys. Polon. 21, 399 (1962).Google Scholar
14 Zhitinskaya, M. K., Kaidanov, V. I., and Chernik, I. A., Sov. Phys.-Sol. Stat. 8 (1), 295–297 (1966).Google Scholar
15 Young, D. L., Coutts, T. J., Kaydanov, V. I., Gilmore, A. S., and Mulligan, W. P., J. Vac. Sci. Technol. A 18 (6), 2978–2985 (2000).Google Scholar