Hostname: page-component-76fb5796d-x4r87 Total loading time: 0 Render date: 2024-04-25T17:06:05.074Z Has data issue: false hasContentIssue false
  • English
  • Français

Electroreflectance Study of Porous Silicon made from Substrates with Different Resistivities

Published online by Cambridge University Press:  17 March 2011

Toshihiko Toyama ,
Yasuharu Nakai  and
Hiroaki Okamoto
Toshihiko Toyama
Affiliation:
Department of Physical Science, Graduate School of Engineering Science, Osaka University Toyonaka, Osaka 560-8531, Japan
Yasuharu Nakai
Affiliation:
Department of Physical Science, Graduate School of Engineering Science, Osaka University Toyonaka, Osaka 560-8531, Japan
Hiroaki Okamoto
Affiliation:
Department of Physical Science, Graduate School of Engineering Science, Osaka University Toyonaka, Osaka 560-8531, Japan
Get access

Abstract

Employing electroreflectance (ER) spectroscopy, we have studied optical transitions in porous Si (PSi) with a thickness of 100±50 nm made from crystalline Si (c-Si) substrates with different resistivities, 4–10 ωcm (p-), 0.1–1 ωcm (p), and < 0.018 ωcm (p+). The ER features observed at 1.1–2.8 eV in p+ PSi are analyzed with a simple effective mass approximation (EMA) model for confined electron-hole (e-h) pairs in a spherical quantum dot as we have previously done for those observed at 1.2–3.1 eV in p- PSi. From the ER analysis with the EMA model, the effective crystal size is estimated without destruction, and the kinetic energy and the Coulomb attraction energy of the confined e-h pairs are also deduced.

Furthermore, the ER features corresponding to the optical transitions at E1(E0') critical point (CP) are observed at 2.8–3.3 eV in p+ PSi. With an increase in the crystal size, the transition energy of E1(E0') CP in p+ PSi is decreased, while that in p- and p PSi is unchanged from that of 3.4 eV found in c-Si including the p+c-Si. From the Raman results, strain- and disorder-induced spectral changes are found to be negligible, so that the high doping induced effect is the most acceptable mechanism for the red-shift in E1(E0') transitions of Si nanocrystals with the crystal size of 2–3 nm.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 638: Symposium F – Microcrystaline & Nanocrystalline Semiconductors-2000 , 2000 , F3.5.1
Copyright
Copyright © Materials Research Society 2001

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. Canham, L. T., Appl. Phys. Lett., 57, 1046 (1990).Google Scholar
2. Yoffe, A. D., Advances in Physics, 42, 173 (1993).Google Scholar
3. Cullis, A. J., Canham, L. T., and Calcott, P. D. J., J. Appl. Phys. 82, 909 (1997).Google Scholar
4. Lehmann, V. and Gösele, U., Appl. Phys. Lett. 58, 856 (1991); G. Bomchil, A. Halimaoui, I. Sagnes, P. A. Badoz, I. Berbezier, P. Perret, B. Lambert, G. Vincent, L. Garchery, and J. L. Regolini, Appl. Surf. Sci. 65/66, 394 (1993).Google Scholar
5. Hilbrich, S., Theiss, W., Arens-Fischer, R., Glück, O., and Berger, M. G., Thin Solid Films, 276, 231 (1996).Google Scholar
6. Pickering, C., Canham, L. T., and Brumhead, D., App. Sur. Sci. 63, 22 (1993); F. Ferrieu, A. Halimaoui, and D. Bensahe, Solid State Comm. 84, 293 (1992).Google Scholar
7. Toyama, T., Shimode, A., and Okamoto, H., Mater. Res. Soc. Symp. Proc. 609 (in press); T. Toyama, Y. Kotani, A. Shimode, and H. Okamoto, Appl. Phys. Lett. 74, 3323 (1999).Google Scholar
8. Cardona, M., Modulation Spectroscopy (Academic Press, New York, 1962).Google Scholar
9. Efros, Al. L. and Efros, A. L., Sov. Phys. Semicond. 16, 772 (1982); L. E. Brus, J. Chem. Phys. 79 5566, (1983); Y. Kayanuma, Phys. Rev. B 38, 9797 (1988).Google Scholar
10. Richter, H., Wang, Z. P. and Ley, L., Solid State Commun. 39, 625 (1981).Google Scholar