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Doping semiconductor nanocrystals

Abstract

Doping—the intentional introduction of impurities into a material—is fundamental to controlling the properties of bulk semiconductors. This has stimulated similar efforts to dope semiconductor nanocrystals1,2,3,4. Despite some successes5,6,7,8,9,10,11, many of these efforts have failed, for reasons that remain unclear. For example, Mn can be incorporated into nanocrystals of CdS and ZnSe (refs 7–9), but not into CdSe (ref. 12)—despite comparable bulk solubilities of near 50 per cent. These difficulties, which have hindered development of new nanocrystalline materials13,14,15, are often attributed to ‘self-purification’, an allegedly intrinsic mechanism whereby impurities are expelled. Here we show instead that the underlying mechanism that controls doping is the initial adsorption of impurities on the nanocrystal surface during growth. We find that adsorption—and therefore doping efficiency—is determined by three main factors: surface morphology, nanocrystal shape, and surfactants in the growth solution. Calculated Mn adsorption energies and equilibrium shapes for several nanocrystals lead to specific doping predictions. These are confirmed by measuring how the Mn concentration in ZnSe varies with nanocrystal size and shape. Finally, we use our predictions to incorporate Mn into previously undopable CdSe nanocrystals. This success establishes that earlier difficulties with doping are not intrinsic, and suggests that a variety of doped nanocrystals—for applications from solar cells16 to spintronics17—can be anticipated.

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Figure 1: Theoretical binding energies for individual Mn adsorbates on various semiconductor surfaces.
Figure 2: Equilibrium crystal shape for cubic systems, as determined by the ratios of their surface energies.
Figure 3: Photoluminescence data and theoretical doping model for ZnSe nanocrystals doped with Mn.
Figure 4: Mn doping of zinc-blende and wurtzite CdSe nanocrystals.

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References

  1. Ekimov, A. I. & Onushchenko, A. A. Quantum size effect in 3-dimensional microscopic semiconductor crystals. JETP Lett. 34, 345–349 (1981)

    ADS  Google Scholar 

  2. Efros, Al. L. & Efros, A. L. Interband absorption of light in a semiconductor sphere. Sov. Phys. Semicond. 16, 772–775 (1982)

    Google Scholar 

  3. Brus, L. E. A simple model for the ionization potential, electron affinity, and aqueous redox potentials of small semiconductor crystallites. J. Chem. Phys. 79, 5566–5571 (1983)

    Article  ADS  CAS  Google Scholar 

  4. Alivisatos, A. P. Semiconductor clusters, nanocrystals, and quantum dots. Science 271, 933–937 (1996)

    Article  ADS  CAS  Google Scholar 

  5. Wang, Y., Herron, N., Moller, K. & Bein, T. 3-dimensionally confined diluted magnetic semiconductor clusters: Zn1–xMnxS. Solid State Commun. 77, 33–38 (1991)

    Article  ADS  CAS  Google Scholar 

  6. Bhargava, R. N., Gallagher, D., Hong, X. & Nurmikko, A. Optical properties of manganese-doped nanocrystals of ZnS. Phys. Rev. Lett. 72, 416–419 (1994)

    Article  ADS  CAS  Google Scholar 

  7. Levy, L., Hochepied, J. F. & Pileni, M. P. Control of the size and composition of three dimensionally diluted magnetic semiconductor clusters. J. Phys. Chem. 100, 18322–18326 (1996)

    Article  CAS  Google Scholar 

  8. Norris, D. J., Yao, N., Charnock, F. T. & Kennedy, T. A. High-quality manganese-doped ZnSe nanocrystals. Nano Lett. 1, 3–7 (2001)

    Article  ADS  CAS  Google Scholar 

  9. Suyver, J. F., Wuister, S. F., Kelly, J. J. & Meijerink, A. Luminescence of nanocrystalline ZnSe:Mn2+. Phys. Chem. Chem. Phys. 2, 5445–5448 (2000)

    Article  CAS  Google Scholar 

  10. Hanif, K. M., Meulenberg, R. W. & Strouse, G. F. Magnetic ordering in doped Cd1–xCoxSe diluted magnetic quantum dots. J. Am. Chem. Soc. 124, 11495–11502 (2002)

    Article  CAS  Google Scholar 

  11. Stowell, C. A., Wiacek, R. J., Saunders, A. E. & Korgel, B. A. Synthesis and characterization of dilute magnetic semiconductor manganese-doped indium arsenide nanocrystals. Nano Lett. 3, 1441–1447 (2003)

    Article  ADS  CAS  Google Scholar 

  12. Mikulec, F. V. et al. Organometallic synthesis and spectroscopic characterization of manganese-doped CdSe nanocrystals. J. Am. Chem. Soc. 122, 2532–2540 (2000)

    Article  CAS  Google Scholar 

  13. Shim, M. & Guyot-Sionnest, P. n-type colloidal semiconductor nanocrystals. Nature 407, 981–983 (2000)

    Article  ADS  CAS  Google Scholar 

  14. Hoffman, D. M. et al. Giant internal magnetic fields in Mn doped nanocrystal quantum dots. Solid State Commun. 114, 547–550 (2000)

    Article  ADS  CAS  Google Scholar 

  15. Efros, Al. L., Rashba, E. I. & Rosen, M. Paramagnetic ion-doped nanocrystal as a voltage-controlled spin filter. Phys. Rev. Lett. 87, 206601 (2001)

    Article  ADS  CAS  Google Scholar 

  16. Huynh, W. U., Dittmer, J. J. & Alivisatos, A. P. Hybrid nanorod-polymer solar cells. Science 295, 2425–2427 (2002)

    Article  ADS  CAS  Google Scholar 

  17. Wolf, S. A. et al. Spintronics: a spin-based electronics vision for the future. Science 294, 1488–1495 (2001)

    Article  ADS  CAS  Google Scholar 

  18. Hwang, I. S., Kim, H. D., Kim, J. E., Park, H. Y. & Lim, H. Solid solubilities of magnetic ions in diluted magnetic semiconductors grown under equilibrium conditions. Phys. Rev. B 50, 8849–8852 (1994)

    Article  ADS  CAS  Google Scholar 

  19. Jamil, N. Y. & Shaw, D. The diffusion of Mn in CdTe. Semicond. Sci. Technol. 10, 952–958 (1995)

    Article  ADS  CAS  Google Scholar 

  20. Shiang, J. J., Kadavanich, A. V., Grubbs, R. K. & Alivisatos, A. P. Symmetry of annealed wurtzite CdSe nanocrystals — assignment to the C3v point group. J. Phys. Chem. 99, 17417–17422 (1995)

    Article  CAS  Google Scholar 

  21. Peng, X. G., Wickham, J. & Alivisatos, A. P. Kinetics of II–VI and III–V colloidal semiconductor nanocrystal growth: ‘Focusing’ of size distributions. J. Am. Chem. Soc. 120, 5343–5344 (1998)

    Article  CAS  Google Scholar 

  22. Kresse, G. & Furthmuller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996)

    Article  ADS  CAS  Google Scholar 

  23. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996)

    Article  ADS  CAS  Google Scholar 

  24. Ji, T. H., Jian, W. B. & Fang, J. Y. The first synthesis of Pb1–xMnxSe nanocrystals. J. Am. Chem. Soc. 125, 8448–8449 (2003)

    Article  CAS  Google Scholar 

  25. Wortis, M. Chemistry and Physics of Solid Surfaces VII Ch. 13 (Springer, Berlin, 1988)

    Google Scholar 

  26. Kasuya, A. et al. Ultra-stable nanoparticles of CdSe revealed from mass spectrometry. Nature Mater. 3, 99–102 (2004)

    Article  ADS  CAS  Google Scholar 

  27. Kaxiras, E. Effect of surface reconstruction on stability and reactivity of Si clusters. Phys. Rev. Lett. 64, 551–554 (1990)

    Article  ADS  CAS  Google Scholar 

  28. Balet, L. P., Ivanov, S. A., Piryatinski, A., Achermann, M. & Klimov, V. I. Inverted core/shell nanocrystals continuously tunable between type-I and type-II localization regimes. Nano Lett. 4, 1485–1488 (2004)

    Article  ADS  CAS  Google Scholar 

  29. Koh, A. K. & Miller, D. J. The systematic variation of the EPR parameters of manganese in II–VI semiconductors. Solid State Commun. 60, 217–222 (1986)

    Article  ADS  CAS  Google Scholar 

  30. Peng, X. G. et al. Shape control of CdSe nanocrystals. Nature 404, 59–61 (2000)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the US Office of Naval Research, the NSF-MRSEC at the University of Minnesota, and NSF-CTS. Computations were performed at the Department of Defense Major Shared Resource Center at ASC. We thank Y. Nesmelov, P. Hasjim and R. Weber for experimental assistance.

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Correspondence to Steven C. Erwin or David J. Norris.

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Supplementary information

Supplementary Discussion

This document lists and discusses the specific surface reconstructions used in the calculations of semiconductor surface energies and of binding energies for Mn adsorbates. (PDF 18 kb)

Supplementary Methods

This document provides a detailed derivation of the optical model used for describing measured photoluminescence intensity ratios. (PDF 48 kb)

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Erwin, S., Zu, L., Haftel, M. et al. Doping semiconductor nanocrystals. Nature 436, 91–94 (2005). https://doi.org/10.1038/nature03832

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