Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-18T06:09:05.750Z Has data issue: false hasContentIssue false
  • English
  • Français

Nmr Study of Ortho-Molecular Hydrogen in Hydrogenated Amorphous Silicon

Published online by Cambridge University Press:  15 February 2011

Tining Su ,
P.C. Taylor ,
Shenlin Chen ,
R.S. Crandall  and
A.H. Mahan
Tining Su
Affiliation:
University of Utah, Department of Physics, Salt Lake City, Utah
P.C. Taylor
Affiliation:
University of Utah, Department of Physics, Salt Lake City, Utah
Shenlin Chen
Affiliation:
University of Utah, Department of Physics, Salt Lake City, Utah
R.S. Crandall
Affiliation:
National Renewable Energy Laboratory, Golden, Colorado.
A.H. Mahan
Affiliation:
National Renewable Energy Laboratory, Golden, Colorado.
Get access

Abstract

A Jeener-Broekaert three-pulse sequence is used to investigate ortho-molecular hydrogen (o-H2) in device quality amorphous silicon films prepared by plasma enhanced chemical vapor deposition (PECVD) and hot wire CVD (HWCVD). For the PECVD sample, the concentration of hydrogen molecules is ~ 11% of the total hydrogen concentration, one order of magnitude larger than that inferred from spin-lattice relaxation time measurements (~1%). Hence, most of the hydrogen molecules do not serve as effective relaxation centers. For HWCVD samples with ~3 to 4% hydrogen and very low void densities, the concentrations of hydrogen molecules are ~1% of the total hydrogen concentration. In these samples, spin-lattice relaxation measurements for bonded hydrogen indicate that the concentration of hydrogen molecules that contribute to spin-lattice relaxation is at most 0.1% of the total hydrogen concentration. Spin-lattice relaxation time (T1) measurements of ortho-molecular hydrogen indicate two very different T1's. The longer T1 is ~ 0.6 s, possibly due to an electric quadrupole-quadrupole (EQQ) interaction between o-H2 molecules and, the shorter T1 is ~ 3 ms, very close to that calculated for a two-phonon Raman process for rotating o-H2.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 557: Symposium A – Amorphous and Heterogeneous Silicon Thin Films—Fundamentals to Devices—1999 , 1999 , 293
Copyright
Copyright © Materials Research Society 1999

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

1. Boyce, J. B., and Stutzmann, M., Phys. Rev. Lett. 54, 562 (1985).Google Scholar
2. Carlos, W. E. and Taylor, P. C., Phys. Rev. B 25, 1435 (1982).Google Scholar
3. Chan, P. H., Ph.D. Thesis, Washington University, September, 1993 (unpublished).Google Scholar
4. Conradi, M. S., Luszczynski, K., and Norberg, R. E., Phys. Rev. B 20, 2594 (1979).Google Scholar
5. Conradi, M. S. and Norberg, R. E., Phys. Rev. B 24 2285 (1981).Google Scholar
6. Drabold, D. A. and Fedders, P. A., Phys. Rev. B 39, 6325 (1989).Google Scholar
7. Fedders, P. A., Phys. Rev. B, 20, 2588 (1979).Google Scholar
8. Fedders, P. A., Fisch, R., and Norberg, R. E., Phys. Rev. B 31, 6887 (1985).Google Scholar
9. Jeener, J. and Broekaert, P., Phys. Rev., 157, 232 (1967).Google Scholar
10. Liu, Xiao, White, B. E. Jr, and Pohl, R. O., Phys. Rev. Lett. 78, 4418 (1997).Google Scholar
11. Norberg, R. E., Leopold, D. J., Fedders, P. A., J. Non-cryst. Solids, 227–230, 124 (1998).Google Scholar
12. Reif, F. and Purcell, E. M., Phys. Rev. 91, 631 (1953).Google Scholar
13. Silvera, I. F., Rev. Mod. Phys. 52, 393 (1980).Google Scholar
14. Hari, P., Taylor, P.C. and Street, R.A., J. Non-Cryst. Solids 198–200, 736 (1996), and references contained therein.Google Scholar