Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Optical gain in silicon nanocrystals

Abstract

Adding optical functionality to a silicon microelectronic chip is one of the most challenging problems of materials research. Silicon is an indirect-bandgap semiconductor and so is an inefficient emitter of light. For this reason, integration of optically functional elements with silicon microelectronic circuitry has largely been achieved through the use of direct-bandgap compound semiconductors. For optoelectronic applications, the key device is the light source—a laser. Compound semiconductor lasers exploit low-dimensional electronic systems, such as quantum wells and quantum dots, as the active optical amplifying medium. Here we demonstrate that light amplification is possible using silicon itself, in the form of quantum dots dispersed in a silicon dioxide matrix. Net optical gain is seen in both waveguide and transmission configurations, with the material gain being of the same order as that of direct-bandgap quantum dots. We explain the observations using a model based on population inversion of radiative states associated with the Si/SiO2 interface. These findings open a route to the fabrication of a silicon laser.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Room temperature absorbance and luminescence of Si nanocrystals embedded in a quartz matrix.
Figure 2: Amplified spontaneous emission intensity (ASE, disks) versus excitation stripe length (l) of Si nanocrystals embedded in a quartz matrix.
Figure 3: Spectral dependence of the net modal gain.
Figure 4: Amplified spontaneous emission spectra of sample A for different measurement conditions.
Figure 5: Gain measurements.
Figure 6: Reciprocal of the rise time τon as a function of the pump laser photon flux as obtained from a fit to the time resolved photoluminescence data shown in the inset.
Figure 7

Similar content being viewed by others

References

  1. Canham, L. T. Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers. Appl. Phys. Lett. 57, 1045– 1048 (1990).

    Article  ADS  Google Scholar 

  2. Cullis, A. G. & Canham, L. T. Visible light emission due to quantum size effects in highly porous crystalline silicon. Nature 353, 335–338 ( 1991).

    Article  ADS  CAS  Google Scholar 

  3. Wilson, W. L., Szajowski, P. F. & Brus, L. E. Quantum confinement in size-selected surface-oxidised silicon nanocrystals. Science 262, 1242– 1244 (1993).

    Article  ADS  CAS  Google Scholar 

  4. Lu, Z. H., Lockwood, D. J. & Baribeau, J.-M. Quantum confinement and light emission in SiO 2/Si superlattices. Nature 378, 258 –260 (1995).

    Article  ADS  CAS  Google Scholar 

  5. Hirschman, K. D., Tsybeskov, L., Duttagupta, S. P. & Fauchet, P. M. Silicon-based light emitting devices integrated into microelectronic circuits. Nature 384, 338–340 (1996).

    Article  ADS  CAS  Google Scholar 

  6. Franzò, G., Priolo, F., Coffa, S., Polman, A. & Carnera, A. Room temperature electroluminescence from Er doped crystalline silicon. Appl. Phys. Lett. 64, 2235– 2237 (1994).

    Article  ADS  Google Scholar 

  7. Leong, D., Harry, M., Reeson, K. J. & Homewood, K. P. A silicon/iron disilicide light-emitting diode operating at a wavelength of 1.5 µm. Nature 387, 686–688 (1997).

    Article  ADS  CAS  Google Scholar 

  8. Nassiopoulos, A. G., Grigoropoulos, S. & Papadimitriou, D. Electroluminescent device based on silicon nanopillars. Appl. Phys. Lett. 69, 2267– 2269 (1996).

    Article  ADS  CAS  Google Scholar 

  9. Bisi, O., Ossicini, S. & Pavesi, L. Porous silicon: a quantum sponge structure for silicon based optoelectronics. Surf. Sci. Rep. 38, 1–126 (2000).

    Article  ADS  CAS  Google Scholar 

  10. Wolkin, M. V., Jorne, J., Fauchet, P. M., Allan, G. & Delerue, C. Electronic states and luminescence in porous silicon quantum dots: the role of oxygen. Phys. Rev. Lett. 82, 197–200 ( 1999).

    Article  ADS  CAS  Google Scholar 

  11. Miller, D. A. Silicon sees the light. Nature 378, 238 (1995).

    Article  ADS  CAS  Google Scholar 

  12. Iyer, S. S. & Xie, Y.-H. Light emission from silicon. Science 260, 40–46 ( 1993).

    Article  ADS  CAS  Google Scholar 

  13. Silicon based optoelectronics. Mater. Res. Bull. 23(4), (1998).

  14. Fauchet, P. M. The integration of nanoscale porous silicon light emitters: materials science, properties and integration with electronic circuitry. J. Lumin. 80, 53–64 ( 1999).

    Article  Google Scholar 

  15. Yariv, A. Quantum Electronics 2nd edn (Wiley & Sons, New York, 1974).

    Google Scholar 

  16. Canham, L. T. in Frontiers of Nano-Optoelectronic Systems (eds Pavesi, L. & Buzaneva, E.) 85–98 (Kluwer Academic, Dordrecht, 2000).

    Book  Google Scholar 

  17. Iacona, F., Franzò, G. & Spinella, C. Correlation between luminescence and structural properties of Si nanocrystals. J. Appl. Phys. 87, 1295 –1303 (2000).

    Article  ADS  CAS  Google Scholar 

  18. Kovalev, D., Heckler, H., Polisski, G. & Koch, F. Optical properties of Si nanocrystals. Phys. Status Solidi 251, 871–930 (1999).

    Article  Google Scholar 

  19. Kanemitsu, Y. & Okamoto, S. Quantum confinement and interface effects on photoluminescence from silicon single quantum wells. Solid State Commun. 103, 573–576 (1997).

    Article  ADS  Google Scholar 

  20. Kanemitsu, Y. & Okamoto, S. Phonon structures and Stokes shift in resonantly excited luminescence of silicon nanocrystals. Phys. Rev. B 58, 9652–9655 ( 1998).

    Article  ADS  CAS  Google Scholar 

  21. Degoli, E. & Ossicini, S. Quantum confined and interface states related visible luminescence in Si/SiO2 superlattices. Surf. Sci. (in the press).

  22. Klimov, V. I., Schwarz, Ch., McBranch, D. W. & White, C. W. Initial carrier relaxation dynamics in ion-implanted Si nanocrystals: femtosecond transient absorption study. Appl. Phys. Lett. 73, 2603–2605 (1998).

    Article  ADS  CAS  Google Scholar 

  23. Linnros, J., Galeckas, A., Lalic, N. & Grivickas, V. Time-resolved photoluminescence characterisation of nm-sized silicon nanocrystallites in SiO2. Thin Solid Films 297, 167 –170 (1997).

    Article  ADS  CAS  Google Scholar 

  24. Shaklee, K. L., Nahaory, R. E. & Leheny, R. F. Optical gain in semiconductors. J. Lumin. 7, 284–309 ( 1973).

    Article  CAS  Google Scholar 

  25. Kirstaedter, N. et al. Gain and differential gain of single layer InAs/GaAs quantum dot injection lasers. Appl. Phys. Lett. 69, 1226–1228 (1996).

    Article  ADS  CAS  Google Scholar 

  26. Lingk, C. et al. Dynamics of amplified spontaneous emission in InAs/GaAs quantum dots. Appl. Phys. Lett. 76, 3507– 3509 (2000).

    Article  ADS  CAS  Google Scholar 

  27. Blood, P. On the dimensionality of optical absorption, gain and recombination in quantum-confined structures. IEEE J. Quantum Electron. 36, 354–362 (2000).

    Article  ADS  CAS  Google Scholar 

  28. Kovalev, D. et al. Optical absorption cross sections of Si nanocrystals. Phys. Rev. B 61, 4485–4487 (2000).

    Article  ADS  CAS  Google Scholar 

  29. von Behren, J., Kostoulas, Y., Ucer, K. B. & Fauchet, P. M. The femtosecond optical response of porous, amorphous and crystalline silicon. J. Non-Cryst. Solids 198–200, 957 –960 (1996).

    Article  ADS  Google Scholar 

  30. Jordan, V. Gain measurements of semiconductor laser diodes: requirements for wavelength resolution and sensitivity to noise. IEE Proc. Optoelectron. 141, 13–15 (1994).

    Article  Google Scholar 

  31. Hvam, J. M. Direct recording of optical gain spectra from ZnO. J. Appl. Phys. 49, 3124–3126 ( 1978).

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

This work has been supported by the National Institute for the Physics of the Matter (INFM) through the LUNA project and the advanced research project RAMSES.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to L. Pavesi.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Pavesi, L., Dal Negro, L., Mazzoleni, C. et al. Optical gain in silicon nanocrystals. Nature 408, 440–444 (2000). https://doi.org/10.1038/35044012

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/35044012

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing