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Visible light emission due to quantum size effects in highly porous crystalline silicon


LIGHT-emitting devices based on silicon would find many applications in both VLSI and display technologies, but silicon normally emits only extremely weak infrared photoluminescence because of its relatively small and indirect band gap1. The recent demonstration of very efficient and multicolour (red, orange, yellow and green) visible light emission from highly porous, electrochemically etched silicon2,3 has therefore generated much interest. On the basis of strong but indirect evidence, this phenomenon was initially attributed to quantum size effects within crystalline material2, but this interpretation has subsequently been extensively debated. Here we report results from a transmission electron microscopy study which reveals the structure of the porous layers that emit red light under photoexcitation. Our results constitute direct evidence that highly porous silicon contains quantum-size crystalline structures responsible for the visible emission. We show that arrays of linear quantum wires are present and obtain images of individual quantum wires of width <3 nm.

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  1. 1

    Haynes, J. R. & Westphal, W. C. Phys. Rev. 101, 1676–1678 (1956).

    ADS  CAS  Article  Google Scholar 

  2. 2

    Canham, L. T. Appl. Phys. Lett. 57, 1046–1048 (1990).

    ADS  CAS  Article  Google Scholar 

  3. 3

    Canham, L. T., Marsh, K. J. & Brumhead, D. Electron. Times 590, 1 (1991).

    Google Scholar 

  4. 4

    Lehmann, V. & Gösele, U. Appl. Phys. Lett. 58, 856–858 (1991).

    ADS  CAS  Article  Google Scholar 

  5. 5

    Bomchil, G., Halimaoui, A. & Herino, R. Micro. Eng. 8, 293–310 (1988).

    CAS  Article  Google Scholar 

  6. 6

    Turner, D. R. J. Electrochem. Soc. 105, 402–408 (1958).

    CAS  Article  Google Scholar 

  7. 7

    Arita, Y. J. Cryst. Growth 45, 383–392 (1978).

    ADS  CAS  Article  Google Scholar 

  8. 8

    Pickering, C., Beale, M. I. J., Robbins, D. J., Pearson, P. J. & Greef, R. J. Phys. C17, 6535–6552 (1984).

    ADS  CAS  Google Scholar 

  9. 9

    Goodes, S. R., Jenkins, T. E., Beale, M. I. J., Benjamin, J. D. & Pickering, C. Semicond. Sci. Technol. 3, 483–487 (1988).

    ADS  CAS  Article  Google Scholar 

  10. 10

    Canham, L. T., Houlton, M. R., Leong, W. Y., Pickering, C. & Keen, J. M. J. appl. Phys. 70, 422–431 (1991).

    ADS  CAS  Article  Google Scholar 

  11. 11

    Phillip, F., Urban, K. & Wilkens, M. Ultramicroscopy 13, 379–386 (1984).

    Article  Google Scholar 

  12. 12

    Beale, M. I. J., Benjamin, J. D., Uren, M. J., Chew, N. G. & Cullis, A. G. J. Cryst. Growth 73, 622–636 (1985).

    ADS  CAS  Article  Google Scholar 

  13. 13

    Chuang, S. F., Collins, S. D. & Smith, R. L. Appl. Phys. Lett. 55, 675–677 (1989).

    ADS  CAS  Article  Google Scholar 

  14. 14

    Sugayama, H. & Nittono, O. J. Cryst. Growth 103, 156–163 (1990).

    ADS  Article  Google Scholar 

  15. 15

    Kaushik, V. S., Datye, A. K., Tsao, S. S., Guilinger, T. R. & Kelly, M. J. Mater. Lett. 11, 109–114 (1991).

    CAS  Article  Google Scholar 

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

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