Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-26T09:22:41.016Z Has data issue: false hasContentIssue false
  • English
  • Français

Variation of Bandgap in Nanocrystalline Silicon as Monitored by Subgap Photoluminescence

Published online by Cambridge University Press:  10 February 2011

A. Kaan Kalkan ,
Sanghoon Bae ,
Shangcong Cheng ,
Yaozu Wang  and
Stephen J. Fonash
A. Kaan Kalkan
Affiliation:
Electronic Materials and Processing Research Laboratory
Sanghoon Bae
Affiliation:
Electronic Materials and Processing Research Laboratory
Shangcong Cheng
Affiliation:
Materials Characterization Laboratory The Pennsylvania State University, University Park, PA 16802
Yaozu Wang
Affiliation:
Electronic Materials and Processing Research Laboratory
Stephen J. Fonash
Affiliation:
Electronic Materials and Processing Research Laboratory
Get access

Abstract

Infrared PL from νc-Si and nc-Si thin films is a potential spectroscopic tool for sensitive diagnostics of structure and defects. Bhat et al. have shown that the dominant PL band found in νc-Si centered at 0.9 eV cannot be assigned to the amorphous phase, as the energeticaly similar defect band found in a-Si:H (i.e., at 0.9 eV) shows a different temperature dependence and is much broader (i.e., FWHM of 0.15 eV compared to 0.35 eV) [1]. Recently, Carius et al. have observed a gradual lower energy shift of the 0.9 eV PL down to 0.82 eV for nc-Si as the plasma deposition excitation frequency is increased with a corresponding decrease in FWHM from 0.15 0.12 eV, respectively [2]. However, a lower energy shift in optical absorption was not observed, nor did they look for a correlation with the variation of any other physical property. Here, we report a broader range of energy variation for PL from our ECR-PECVD deposited nc-Si films accompanied with an energy shift in optical absorption and variation in dark conductivity and crystallite size. It has been argued that this PL peak in question could arise from the radiative transitions between bandtail states as in the case of ∼1.3 eV PL in a-Si:H or it may be associated with structural defects [2,3]. Our observations support both possibilities.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 507: Symposium A – Amorphous & Microcrystalline Silicon Technology 1998 , 1998 , 291
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 Bhat, P.K., Diprose, G., Searle, T.M., Austin, I.G., P.G. LeComber and Spear, W.E., Physica 117B and 118B, p. 917 (1983).Google Scholar
2 Carius, R., Finger, F., Backhausen, U., Luysberg, M., Hapke, P., Houpen, L., Otte, M. and Overhof, H., Mater. Res. Soc. Proc. 467, p. 283 (1997).Google Scholar
3 Savchouk, A.U., Ostapenko, S., Novak, G., Lagowski, J. and Jastrzebski, L., Appl. Phys. Lett. 67, p. 82 (1995).Google Scholar
4 Street, R. A., in Semiconductors and Semimetals 2 1, Part B, edited by Pankove, J.I., p.197, Academic Press (1984).Google Scholar
5 Veprek, S., Iqbal, Z., Oswald, H.R. and Webb, A.P., J. Phys. C14, p. 295 (1981).Google Scholar
6 Okada, Y., Campbell, I.H., Fauchet, P.M. and Wagner, S., Mat. Res. Soc. Symp. Proc. 164, p. 15 (1990).Google Scholar
7 Kroll, U., Meier, J., Keppner, H., Littlewood, S.D., Kelly, I.E., Giannoules, P. and Shah, A., Mat. Res. Soc. Symp. Proc. 377, p. 39 (1995).Google Scholar
8 Kimmerling, L.C. and Benton, J.L., Appl. Phys. Lett. 39, p. 410 (1981).Google Scholar
9 Gaworzewski, P. and Schmalz, K., Phys. Stat. Sol. A55, p. 699 (1979).Google Scholar
10 Williams, M.J., Wang, C., Lucovsky, G., J. Non-Cryst. Solids 137 and 138, p. 737 (1991).Google Scholar
11 Meier, J., Torres, P., Platz, R., Dubail, S., Kroll, U., Selvan, J. A. A., Vaucher, N. Pellaton, Hof, Ch., Fischer, D., Keppner, H., Shah, A., Ufert, K. D., Giannoules, P., and Koehler, J., Mat. Res. Soc. Symp. Proc. 420, p. 3 (1996).Google Scholar
12 Qian, Y.H., Evans, J.H., Giles, L.F., Nejim, A. and Hemment, P.L.F., Mat. Res. Soc. Proc. 378, p. 629 (1995).Google Scholar
13 Duncan, W.M., Chang, P.H., Mao, B.Y. and Chen, C.E., Appl. Phys. Lett. 51, 773 (1987).Google Scholar
14 Drozdov, N.A., Patrin, A.A. and Tkachev, V.D., Phys. Stat. Solidi B83, K137 (1977).Google Scholar
15 Beck, N., Meier, J., Fric, J., Remes, Z., Poruba, A., Fluckiger, R., Pohl, J., Shah, A., Vanecek, M., J. Non-Cryst. Solids 198–200, p. 903 (1996).Google Scholar
16 Collins, R.W., Paesler, M.A. and Paul, W., Sol. State. Commun. 34, p 833 (1980).Google Scholar