Abstract

We have measured the one-photon, resonant nonlinear optical properties of sputter-deposited nanocomposite CdS:ZnO thin films with a characteristic grain size of about 3 nm. These films show a completely reversible photodarkening at low fluences as well as fast recovery, making them useful for optical limiting applications. The observed photoresponse can be ascribed to excited-state absorption and is in good agreement with a semiquantitative, four-level model proposed by us.

© 2006 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. U. Woggon, Optical Properties of Semiconductor Quantum Dots (Springer, 1997).
  2. L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
    [CrossRef] [PubMed]
  3. W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
    [CrossRef] [PubMed]
  4. C. Bowden, M. Dagenais, E. M. Garmire, F. J. Leonberger, N. Peyghambarian, G. I. Stegeman, and P. A. Wolff, "Research on nonlinear optical materials: an assessment. II. Bulk semiconductors," Appl. Opt. 26, 213-215 (1987).
    [CrossRef] [PubMed]
  5. M. G. Bawendi, P. J. Carroll, W. L. Wilson, and L. E. Brus, "Luminescence properties of CdSe quantum crystallites: resonance between interior and surface localized states," J. Chem. Phys. 96, 946-954 (1992).
    [CrossRef]
  6. M. G. Bawendi, A. R. Kortan, M. L. Steigerwald, and L. E. Brus, "X-ray structural characterization of larger CdSe semiconductor clusters," J. Chem. Phys. 91, 7282-7290 (1989).
    [CrossRef]
  7. L. Liu and S. H. Risbud, "Quantum-dot size-distribution analysis and precipitation stages in semiconductor doped glasses," J. Appl. Phys. 68, 28-32 (1990).
    [CrossRef]
  8. P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
    [CrossRef]
  9. P. Roussignol, D. Ricard, J. Lukasik, and C. Flytzanis, "New results on optical phase conjugation in semiconductor-doped glasses," J. Opt. Soc. Am. B 4, 5-13 (1987).
    [CrossRef]
  10. J. Malhotra, D. J. Hagan, and B. G. Potter, "Laser-induced darkening in semiconductor-doped glasses," J. Opt. Soc. Am. B 8, 1531-1536 (1991).
    [CrossRef]
  11. F. Hache, M. C. Klein, D. Ricard, and C. Flytzanis, "Photoluminescence study of Schott commercial and experimental CdSSe-doped glasses: observation of surface states," J. Opt. Soc. Am. B 8, 1802-1806 (1991).
    [CrossRef]
  12. P. Vasa, P. Ayyub, and B. P. Singh, "Fast and reversible excited state absorption in II-VI-based nanocomposite thin films," Appl. Phys. Lett. 87, 063104 (2005).
    [CrossRef]
  13. A. D. Yoffe, "Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systems," Adv. Phys. 42, 173-266 (1993).
    [CrossRef]
  14. P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
    [CrossRef]
  15. P. Taneja, P. Vasa, and P. Ayyub, "Chemical passivation of sputter-deposited nanocrystalline CdS thin films," Mater. Lett. 54, 343-347 (2002).
    [CrossRef]
  16. R. L. Sutherland, Handbook of Nonlinear Optics (Marcel Dekker, 1996).
  17. M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
    [CrossRef]
  18. P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
    [CrossRef]
  19. P. Vasa, B. P. Singh, and P. Ayyub, "Coherence properties of the photoluminescence from CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 17, 189-197 (2005).
    [CrossRef]

2005 (3)

P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
[CrossRef]

P. Vasa, P. Ayyub, and B. P. Singh, "Fast and reversible excited state absorption in II-VI-based nanocomposite thin films," Appl. Phys. Lett. 87, 063104 (2005).
[CrossRef]

P. Vasa, B. P. Singh, and P. Ayyub, "Coherence properties of the photoluminescence from CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 17, 189-197 (2005).
[CrossRef]

2002 (2)

P. Taneja, P. Vasa, and P. Ayyub, "Chemical passivation of sputter-deposited nanocrystalline CdS thin films," Mater. Lett. 54, 343-347 (2002).
[CrossRef]

P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
[CrossRef]

2001 (2)

P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
[CrossRef]

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

2000 (1)

L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
[CrossRef] [PubMed]

1993 (1)

A. D. Yoffe, "Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systems," Adv. Phys. 42, 173-266 (1993).
[CrossRef]

1992 (1)

M. G. Bawendi, P. J. Carroll, W. L. Wilson, and L. E. Brus, "Luminescence properties of CdSe quantum crystallites: resonance between interior and surface localized states," J. Chem. Phys. 96, 946-954 (1992).
[CrossRef]

1991 (2)

1990 (2)

M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
[CrossRef]

L. Liu and S. H. Risbud, "Quantum-dot size-distribution analysis and precipitation stages in semiconductor doped glasses," J. Appl. Phys. 68, 28-32 (1990).
[CrossRef]

1989 (1)

M. G. Bawendi, A. R. Kortan, M. L. Steigerwald, and L. E. Brus, "X-ray structural characterization of larger CdSe semiconductor clusters," J. Chem. Phys. 91, 7282-7290 (1989).
[CrossRef]

1987 (2)

Ayyub, P.

P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
[CrossRef]

P. Vasa, P. Ayyub, and B. P. Singh, "Fast and reversible excited state absorption in II-VI-based nanocomposite thin films," Appl. Phys. Lett. 87, 063104 (2005).
[CrossRef]

P. Vasa, B. P. Singh, and P. Ayyub, "Coherence properties of the photoluminescence from CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 17, 189-197 (2005).
[CrossRef]

P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
[CrossRef]

P. Taneja, P. Vasa, and P. Ayyub, "Chemical passivation of sputter-deposited nanocrystalline CdS thin films," Mater. Lett. 54, 343-347 (2002).
[CrossRef]

P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
[CrossRef]

Banerjee, R.

P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
[CrossRef]

P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
[CrossRef]

Bawendi, M. G.

M. G. Bawendi, P. J. Carroll, W. L. Wilson, and L. E. Brus, "Luminescence properties of CdSe quantum crystallites: resonance between interior and surface localized states," J. Chem. Phys. 96, 946-954 (1992).
[CrossRef]

M. G. Bawendi, A. R. Kortan, M. L. Steigerwald, and L. E. Brus, "X-ray structural characterization of larger CdSe semiconductor clusters," J. Chem. Phys. 91, 7282-7290 (1989).
[CrossRef]

Bowden, C.

Brus, L. E.

M. G. Bawendi, P. J. Carroll, W. L. Wilson, and L. E. Brus, "Luminescence properties of CdSe quantum crystallites: resonance between interior and surface localized states," J. Chem. Phys. 96, 946-954 (1992).
[CrossRef]

M. G. Bawendi, A. R. Kortan, M. L. Steigerwald, and L. E. Brus, "X-ray structural characterization of larger CdSe semiconductor clusters," J. Chem. Phys. 91, 7282-7290 (1989).
[CrossRef]

Carroll, P. J.

M. G. Bawendi, P. J. Carroll, W. L. Wilson, and L. E. Brus, "Luminescence properties of CdSe quantum crystallites: resonance between interior and surface localized states," J. Chem. Phys. 96, 946-954 (1992).
[CrossRef]

Chandra, R.

P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
[CrossRef]

Dagenais, M.

Flytzanis, C.

Franzo, G.

L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
[CrossRef] [PubMed]

Garmire, E. M.

Gwilliam, R. M.

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

Hache, F.

Hagan, D. J.

J. Malhotra, D. J. Hagan, and B. G. Potter, "Laser-induced darkening in semiconductor-doped glasses," J. Opt. Soc. Am. B 8, 1531-1536 (1991).
[CrossRef]

M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
[CrossRef]

Homewood, K. P.

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

Klein, M. C.

Kortan, A. R.

M. G. Bawendi, A. R. Kortan, M. L. Steigerwald, and L. E. Brus, "X-ray structural characterization of larger CdSe semiconductor clusters," J. Chem. Phys. 91, 7282-7290 (1989).
[CrossRef]

Ledain, S.

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

Leonberger, F. J.

Liu, L.

L. Liu and S. H. Risbud, "Quantum-dot size-distribution analysis and precipitation stages in semiconductor doped glasses," J. Appl. Phys. 68, 28-32 (1990).
[CrossRef]

Lourenco, M. A.

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

Lukasik, J.

Malhotra, J.

Mazzoleni, C.

L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
[CrossRef] [PubMed]

Negro, L. D.

L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
[CrossRef] [PubMed]

Ng, W. L.

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

Pavesi, L.

L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
[CrossRef] [PubMed]

Peyghambarian, N.

Pinto, R.

P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
[CrossRef]

Potter, B. G.

Priolo, F.

L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
[CrossRef] [PubMed]

Ricard, D.

Risbud, S. H.

L. Liu and S. H. Risbud, "Quantum-dot size-distribution analysis and precipitation stages in semiconductor doped glasses," J. Appl. Phys. 68, 28-32 (1990).
[CrossRef]

Roussignol, P.

Said, A. A.

M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
[CrossRef]

Shao, G.

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

Sharma, A. K.

P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
[CrossRef]

Sheik-Bahae, M.

M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
[CrossRef]

Singh, B. P.

P. Vasa, B. P. Singh, and P. Ayyub, "Coherence properties of the photoluminescence from CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 17, 189-197 (2005).
[CrossRef]

P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
[CrossRef]

P. Vasa, P. Ayyub, and B. P. Singh, "Fast and reversible excited state absorption in II-VI-based nanocomposite thin films," Appl. Phys. Lett. 87, 063104 (2005).
[CrossRef]

P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
[CrossRef]

Stegeman, G. I.

Steigerwald, M. L.

M. G. Bawendi, A. R. Kortan, M. L. Steigerwald, and L. E. Brus, "X-ray structural characterization of larger CdSe semiconductor clusters," J. Chem. Phys. 91, 7282-7290 (1989).
[CrossRef]

Sutherland, R. L.

R. L. Sutherland, Handbook of Nonlinear Optics (Marcel Dekker, 1996).

Taneja, P.

P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
[CrossRef]

P. Taneja, P. Vasa, and P. Ayyub, "Chemical passivation of sputter-deposited nanocrystalline CdS thin films," Mater. Lett. 54, 343-347 (2002).
[CrossRef]

P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
[CrossRef]

P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
[CrossRef]

Van Stryland, E. W.

M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
[CrossRef]

Vasa, P.

P. Vasa, B. P. Singh, and P. Ayyub, "Coherence properties of the photoluminescence from CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 17, 189-197 (2005).
[CrossRef]

P. Vasa, P. Ayyub, and B. P. Singh, "Fast and reversible excited state absorption in II-VI-based nanocomposite thin films," Appl. Phys. Lett. 87, 063104 (2005).
[CrossRef]

P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
[CrossRef]

P. Taneja, P. Vasa, and P. Ayyub, "Chemical passivation of sputter-deposited nanocrystalline CdS thin films," Mater. Lett. 54, 343-347 (2002).
[CrossRef]

P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
[CrossRef]

Wei, T. H.

M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
[CrossRef]

Wilson, W. L.

M. G. Bawendi, P. J. Carroll, W. L. Wilson, and L. E. Brus, "Luminescence properties of CdSe quantum crystallites: resonance between interior and surface localized states," J. Chem. Phys. 96, 946-954 (1992).
[CrossRef]

Woggon, U.

U. Woggon, Optical Properties of Semiconductor Quantum Dots (Springer, 1997).

Wolff, P. A.

Yoffe, A. D.

A. D. Yoffe, "Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systems," Adv. Phys. 42, 173-266 (1993).
[CrossRef]

Adv. Phys. (1)

A. D. Yoffe, "Low-dimensional systems: quantum size effects and electronic properties of semiconductor microcrystallites (zero-dimensional systems) and some quasi-two-dimensional systems," Adv. Phys. 42, 173-266 (1993).
[CrossRef]

Appl. Opt. (1)

Appl. Phys. A (1)

P. Ayyub, R. Chandra, P. Taneja, A. K. Sharma, and R. Pinto, "Synthesis of nanocrystalline material by sputtering and laser ablation at low temperature," Appl. Phys. A 73, 67-73 (2001).
[CrossRef]

Appl. Phys. Lett. (1)

P. Vasa, P. Ayyub, and B. P. Singh, "Fast and reversible excited state absorption in II-VI-based nanocomposite thin films," Appl. Phys. Lett. 87, 063104 (2005).
[CrossRef]

IEEE J. Quantum Electron. (1)

M. Sheik-Bahae, A. A. Said, T. H. Wei, D. J. Hagan, and E. W. Van Stryland, "Sensitive measurement of optical nonlinearities using a single beam," IEEE J. Quantum Electron. 26, 760-769 (1990)
[CrossRef]

J. Appl. Phys. (2)

L. Liu and S. H. Risbud, "Quantum-dot size-distribution analysis and precipitation stages in semiconductor doped glasses," J. Appl. Phys. 68, 28-32 (1990).
[CrossRef]

P. Ayyub, P. Vasa, P. Taneja, R. Banerjee, and B. P. Singh, "Photoluminescence enhancement in nanocomposite thin films of CdS-ZnO," J. Appl. Phys. 97, 104310 (2005).
[CrossRef]

J. Chem. Phys. (2)

M. G. Bawendi, P. J. Carroll, W. L. Wilson, and L. E. Brus, "Luminescence properties of CdSe quantum crystallites: resonance between interior and surface localized states," J. Chem. Phys. 96, 946-954 (1992).
[CrossRef]

M. G. Bawendi, A. R. Kortan, M. L. Steigerwald, and L. E. Brus, "X-ray structural characterization of larger CdSe semiconductor clusters," J. Chem. Phys. 91, 7282-7290 (1989).
[CrossRef]

J. Opt. Soc. Am. B (3)

J. Phys.: Condens. Matter (2)

P. Vasa, P. Taneja, P. Ayyub, B. P. Singh, and R. Banerjee, "Photoconductivity in sputter-deposited CdS and CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 14, 281-286 (2002).
[CrossRef]

P. Vasa, B. P. Singh, and P. Ayyub, "Coherence properties of the photoluminescence from CdS-ZnO nanocomposite thin films," J. Phys.: Condens. Matter 17, 189-197 (2005).
[CrossRef]

Mater. Lett. (1)

P. Taneja, P. Vasa, and P. Ayyub, "Chemical passivation of sputter-deposited nanocrystalline CdS thin films," Mater. Lett. 54, 343-347 (2002).
[CrossRef]

Nature (2)

L. Pavesi, L. D. Negro, C. Mazzoleni, G. Franzo, and F. Priolo, "Optical gain in silicon nanocrystals," Nature 408, 440-444 (2000).
[CrossRef] [PubMed]

W. L. Ng, M. A. Lourenco, R. M. Gwilliam, S. Ledain, G. Shao, and K. P. Homewood, "An efficient room-temperature silicon-based light-emitting diode," Nature 410, 192-194 (2001).
[CrossRef] [PubMed]

Other (2)

R. L. Sutherland, Handbook of Nonlinear Optics (Marcel Dekker, 1996).

U. Woggon, Optical Properties of Semiconductor Quantum Dots (Springer, 1997).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (3)

Fig. 1
Fig. 1

PL emission from a nano-CdS:ZnO (n-CZ2) thin film at 591nm as a function of incident intensity, excited by the second harmonic of a Ti:sapphire laser ( 390 nm , 80 fs, 100 MHz, 40 mW) and collected normal to the incident direction. Inset shows the PL spectra for the same sample, recorded from points at and away from the focus (which are therefore excited at different intensities).

Fig. 2
Fig. 2

Transmission of the probe beam (multiline Ar + laser, 12 mW) in the presence and absence of the pump beam (second harmonic of a Ti:sapphire laser: 390 nm, 80 fs, 100 MHz, 20 mW) for nano-CdS:ZnO (n-CZ2). The accuracy in the response time measurement is ± 10 % . Solid curve, the fit based on a semiquantitative four-level model (Section 3).

Fig. 3
Fig. 3

Schematic energy level diagram for the proposed four-level model. States other than the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular obital (LUMO) levels are generated by defects. The positions of the states indicated in the diagram do not denote the actual energies. Approximate time scales and decay rates (or absorption cross sections) for each transition are also shown.

Tables (1)

Tables Icon

Table 1 Measured Optical Parameters for the Nanocrystalline CdS and Nanocomposite CdS:ZnO Thin Films a

Equations (13)

Equations on this page are rendered with MathJax. Learn more.

d n 3 d t = β I ( t ) Γ n 3 ,
d n 2 d t = γ b n 3 γ c n 2 ,
d n 1 d t = β I ( t ) + γ a n 3 + γ c n 2 ,
n 1 + n 2 + n 3 = N ,
n 3 ( t ) = β I Γ [ 1 exp ( Γ t ) ] .
n 2 ( t ) = β I γ b γ c Γ [ 1 exp ( γ c t ) ] + β I γ b Γ ( γ c Γ ) [ exp ( Γ t ) exp ( γ c t ) ] .
n 2 ( t ) = β I γ b γ c Γ [ 1 exp ( γ c t ) ]
n 2 ( t ) = β I γ b γ c Γ [ exp ( γ c T p ) 1 ] exp ( γ c t )
d I 2 d z = σ 2 n 2 ( t ) I 2 ,
I tr = I 2 exp ( σ 2 n 2 L ) ,
I tr 1 β I γ b γ c Γ [ 1 exp ( γ c t ) ] ( ON period ) ,
I tr 1 β I γ b γ c Γ [ exp ( γ c T p ) 1 ] exp ( γ c t ) ( OFF period ) .
y = y 0 + A exp ( B t ) ,

Metrics