Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T17:41:29.416Z Has data issue: false hasContentIssue false

Molecular Hydrogen in Hot-Wire Hydrogenated Amorphous Silicon

Published online by Cambridge University Press:  10 February 2011

Xiao. Liu
Affiliation:
Department of Physics, Cornell University, Ithaca, NY 14853-2501
E. Iwaniczko
Affiliation:
National Renewable Energy Laboratory, Golden, CO 80401
R.O. Pohl
Affiliation:
Department of Physics, Cornell University, Ithaca, NY 14853-2501, [email protected]
R.S. Crandall
Affiliation:
National Renewable Energy Laboratory, Golden, CO 80401
Get access

Abstract

We have studied the elastic properties of hydrogenated amorphous silicon (a-Si:H) prepared by hot wire chemical-vapor deposition (HWCVD). With 1 at.% H, this material has been found to be the only amorphous solid which has a low-temperature internal friction more than two orders of magnitude smaller than all other amorphous solids studied to date, as reported recently. As the hydrogen concentration increases above 1 at.%, a broad relaxation peak in internal friction around 5 K is observed. Even more striking is an extremely narrow peak in internal friction accompanied by a discontinuous change in the sound velocity at 13.8 K, which coincides with the triple point temperature of molecular hydrogen. Evidences are provided to show that this anomaly is caused by bulk molecular hydrogen which undergoes a liquid-solid phase transition. This is the first observation for the existence of bulk H2 in HWCVD a-Si:H.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Conradi, M. S. and Norberg, R. E., Phys. Rev B 24, 2285 (1981).Google Scholar
2 Carlos, W. E. and Taylor, P. C., Phys. Rev. B 25, 1435 (1982).Google Scholar
3 Graebner, J. E., Golding, B., Allen, L. C., Biegelsen, D. K., and Sturzmann, M., Phys. Rev. Lett. 52, 553 (1984); J. E. Graebner, L. C. Allen, B. Golding, Phys. Rev. B 31, 904 (1985).Google Scholar
4 Löhneysen, H. v., Schink, H. J., and Beyer, W., Phys. Rev. Lett. 52, 549 (1984).Google Scholar
5 Chabal, Y. J. and Patel, C. K. N., Phys. Rev. Lett. 53, 210 (1984); ibid. 53, 1771 (1984).Google Scholar
6 Liu, X., White, B. E. Jr., Pohl, R. O., Iwanizcko, E., Jones, K. M., Mahan, A. H., Nelson, B. N., and Crandall, R. S., Phys. Rev. Lett. 78, 4418 (1997).Google Scholar
7 For a review, see Amorphous Solids: Low Temperature Properties, edited by Phillips, W. A., Springer-Verlag, Berlin, 1981.Google Scholar
8 White, B. E. Jr., and Pohl, R. O., in Thin Films: Stresses and Mechanical properties V, edited by Baker, S. P., Ross, C. A., Townsend, P. H., Volkert, C. A., Borgesen, P., (Mat. Res. Soc. Sym. Proc. 356, Pittsburgh, PA 1995), pp. 567572.Google Scholar
9 Remes, Z., Vanecek, M., Mahan, A. H., and Crandall, R. S., Phys. Rev. B 56, R12710 (1997).Google Scholar
10 Williamson, D. L., Roorda, S., Chicoine, M., Tabti, R., Stolk, P. A., Acco, S., and Saris, F. W., Appl. Phys. Lett. 67, 226 (1995).Google Scholar
11 Vacher, R., Sussner, H., and Schmidt, M., Solid State Commun. 34, 279 (1980).Google Scholar
12 Mahan, A. H., Carapella, J., Nelson, B. P., Crandall, R. S., Balberg, I., J. Appl. Phys. 69, 6728 (1991).Google Scholar
13 Scott, R. B., Cryogenic Engineering, D. Van Nostrand Company, Inc., New York, 1959, p. 291.Google Scholar
14 Mahan, A. H. and Vanecek, M., in Amorphous Silicon Materials and Solar Cells, edited by Stafford, B. L., AIP, New York, 1991, pp. 195.Google Scholar
15 Tell, J. L. and Maris, H. J., Phys. Rev. B 28, 5122 (1983).Google Scholar
16 Liu, F.-C., Liu, T.-M., and Vilches, O. E., Phys. Rev. B 51, 2848 (1995).Google Scholar
17 Gordillo, M. C. and Ceperley, D. M., Phys. Rev. Lett. 79, 3010 (1997), and references therein.Google Scholar
18 Staebler, D. L. and Wronski, C. R., Appl. Phys. Lett. 31, 292 (1977).Google Scholar