Hostname: page-component-848d4c4894-8bljj Total loading time: 0 Render date: 2024-06-25T05:18:44.205Z Has data issue: false hasContentIssue false
  • English
  • Français

Effect of C Impurities in a-Si:H as Measured by Drive-Level Capacitance, Photo Current, and Electron Spin Resonance

Published online by Cambridge University Press:  01 January 1993

J. Hautala ,
T. Unold  and
J.D. Cohen
J. Hautala
Affiliation:
University of Oregon, Department of Physics, Eugene OR 97403
T. Unold
Affiliation:
University of Oregon, Department of Physics, Eugene OR 97403
J.D. Cohen
Affiliation:
University of Oregon, Department of Physics, Eugene OR 97403
Get access

Abstract

The effect of C impurities in a-Si:H in levels of 0.4 to 2.6 at. % were studied over a wide range of metastable defect densities. Three complimentary experimental techniques [electron spin resonance (ESR), drive-level capacitance (DLC) and photo-current] were employed to track the material's defect density with light soaking and annealing, as well as Urbach energies, midgap absorption and mobility gaps energies as a function of the C content. Our results show C impurities have a definite effect on the initial and saturated defect densities, as well as the midgap absorption and Urbach energies at levels 1 at. % and above. The results indicate that C acts mainly as a center for increased disorder in the material which results in an increase in the bandtail widths, and consequently an increase in intrinsic defects. Comparison to the ESR and drive-level data show an excellent agreement between these two techniques in determining the bulk defect densities in a-Si:H.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 297: Symposium A – Amorphous Silicon Technology - 1993 , 1993 , 375
Copyright
Copyright © Materials Research Society 1993

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. Carlson, D.E., Catalano, A., D'Aiello, R.V., Dickson, C.R. and Oswald, R.S., in Optical Effects in Amorphous Semiconductors, edited by Taylor, P.C. and Bishop, S.G. (AIP, New York, 1984), Conf. No. 120, p. 234.Google Scholar
2. Crandall, R.S., Carlson, D.E., Catalano, A. and Weakliem, H.A., Appl. Phys. Lett. 44, 200 (1984).Google Scholar
3. Mahadavi, K. K., Zellama, K., Cohen, J.D. and Harbison, J.P., Phys. Rev. B 35, 7776 (1987).Google Scholar
4. Unold, T. and Cohen, J.D., Appl. Phys. Lett. 58, 723 (1990).Google Scholar
5. Stutzmann, M., Jackson, W.B. and Tsai, C.C., Phys. Rev. B 32, 23 (1985).Google Scholar
6. Skumanich, A. and Amer, N.M., Phys. Rev. B 37, 8465 (1988).Google Scholar
7. Shimizu, T., Matsumoto, M., Yoshita, M., Iwami, M., Morimoto, A. and Kumeda, M., J. Non-Cryst. Solids 137 & 138, 391 (1991).Google Scholar
8. Morimoto, A., Matsumoto, M., Kumeda, M. and Shimizu, T., Jpn. J. Appl. Phys. 29, 1747 (1990).Google Scholar
9. Stutzmann, M., Phil. Mag. B 60, 531 (1989).Google Scholar
10. Stutzmann, M., Phil. Mag. L 66, 147 (1992).Google Scholar
11.SIMS analysis was perfored at NREL by Sally Asher.Google Scholar
12. Michelson, C.E., Gelatos, A.V. and Cohen, J.D., Appl. Phys. Lett. 47, 412 (1985).Google Scholar
13. Cohen, J.D. and Gelatos, A.V., in Advances in Disordered Semiconductors Vol I: Amorphous Silicon and Related Materials, ed. by Fritzsche, H. (World Scientific, Singapore, 1988), pp 475–512.Google Scholar
14. Cohen, J.D., Unold, T., Gelatos, A.V. and Fortman, C.M., J. Non-Cryst. Solids 141, 142 (1992).Google Scholar
15. Unold, T., Cohen, J.D. and Fortman, C.M., Amorphous Silicon (Mat. Res. Soc. Symp. Proc. 258, 1992) pp.499.Google Scholar
16. Unold, T., Ph.D. Thesis, University of Oregon, (1993).Google Scholar
17. Unold, T. and Cohen, J.D., published this volume.Google Scholar