LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
An, J.M.; Califano, M.; Franceschetti, A.; Zunger, A. (2008)
Publisher: American Institute of Physics
Languages: English
Types: Article
Subjects:
In solids the phonon-assisted, nonradiative decay from high-energy electronic excited states to low-energy electronic excited states is picosecond fast. It was hoped that electron and hole relaxation could be slowed down in quantum dots, due to the unavailability of phonons energy matched to the large energy-level spacings (“phonon-bottleneck”). However, excited-state relaxation was observed to be rather fast (1 ps) in InP, CdSe, and ZnO dots, and explained by an efficient Auger mechanism, whereby the excess energy of electrons is nonradiatively transferred to holes, which can then rapidly decay by phonon emission, by virtue of the densely spaced valence-band levels. The recent emergence of PbSe as a novel quantum-dot material has rekindled the hope for a slow down of excited-state relaxation because hole relaxation was deemed to be ineffective on account of the widely spaced hole levels. The assumption of sparse hole energy levels in PbSe was based on an effective-mass argument based on the light effective mass of the hole. Surprisingly, fast intraband relaxation times of 1–7 ps were observed in PbSe quantum dots and have been considered contradictory with the Auger cooling mechanism because of the assumed sparsity of the hole energy levels. Our pseudopotential calculations, however, do not support the scenario of sparse hole levels in PbSe: Because of the existence of three valence-band maxima in the bulk PbSe band structure, hole energy levels are densely spaced, in contradiction with simple effective-mass models. The remaining question is whether the Auger decay channel is sufficiently fast to account for the fast intraband relaxation. Using the atomistic pseudopotential wave functions of Pb2046Se2117 and Pb260Se249 quantum dots, we explicitly calculated the electron-hole Coulomb integrals and the PS electron Auger relaxation rate. We find that the Auger mechanism can explain the experimentally observed PS intraband decay time scale without the need to invoke any exotic relaxation mechanisms.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • [1] C.H. Henry and D.V. Lang, IEEE Transactions of Electron Devices Ed. 21, 745, 1974, Cambridge, 1991.
    • [2] R. Englman and J. Jortner, Molecular Physics 18, 145 (1970).
    • [3] B. L. Wehrenberg, C. Wang, and P. Guyot-Sionnest, J. Phys. Chem. B 106, 10634 (2002).
    • [4] A. Nozik, Physica E 14, 115 (2002).
    • [5] U. Bockelmann and G. Bastard, Phys. Rev. B 42, 8947 (1990).
    • [6] H. Benisty, C. M. Sotomayor-Torr`es, and C. Weisbuch, Phys. Rev. B 44, 10945 (1991).
    • [7] V. I. Klimov, D. W. McBranch, C. A. Leatherdale, and M. G. Bawendi, Phys. Rev. B 60, 13740 (1999).
    • [8] P. Liljeroth, P. A. Z. van Emmichoven, S. G. Hickey, H. Weller, B. Grandidier, G. Allan, and D. Vanmaekelbergh, Phys. Rev. Lett. 95, 086801 (2005).
    • [9] J. M. An, A. Franceschetti, S. V. Dudiy, and A. Zunger, Nano Letters 6, 2728 (2006).
    • [10] A. Franceschetti, J. M. An, and A. Zunger, Nano Letters 6, 2191 (2006).
    • [11] Landolt and B¨ortstein, group III Condensed Matter, Vol. 41, Issue 0, Jan 1998, Springer-Verlag, Berlin.
    • [12] R. D. Schaller, J. M. Pietryga, S. V. Goupalov, M. A. Petruska, S. A. Ivanov, and V. I. Klimov, Phys. Rev. Lett. 95, 196401 (2005).
    • [13] G. A. Narvaez, G. Bester, and A. Zunger, Phys. Rev. B 74, 075403 (2006).
    • [14] S. Hameau, Y. Guldner, O. Verzelen, R. Ferreira, and G. Bastard, Phys. Rev. Lett. 83, 4152 (1999).
    • [15] V. M. Fomin, V. Gladilin, J. Devreese, E. Pokatilov, S. N. Balaban, and S. Klimin, Solid State Comm. 105, 113 (1998).
    • [16] V. M. Fomin, E. Pokatilov, J. Devreese, S. Klimin, V. Gladilin, and S. N. Balaban, Solid State Comm. 42, 1309 (1998).
    • [17] If strong electron-lattice coupling exists, the adiabatic approximation breaks down, leading to no phononbottleneck, even if there is some energetic mismatch. See Ref. 14-16.
    • [18] V. I. Klimov and D. W. McBranch, Phys. Rev. Lett. 80, 4028 (1998).
    • [19] P. Guyot-Sionnest, M. Shim, C. Matranga, and M. Hines, Phys. Rev. B 60, R2181 (1999).
    • [20] C. Burda, S. Link, M. Mohamed, and M. El-Sayed, J. Phys. Chem. B 105, 12 286 (2001).
    • [21] U. Woggon, H. Giessen, F. Gindele, O. Wind, B. Fluegel, and N. Peyghambarian, Phys. Rev. B 54, 17681 (1996).
    • [22] M. Shim and P. Guyot-Sionnest, Phys. Rev. B 64, 245342 (2001).
    • [23] T. S. Sosnowski, T. B. Norris, H. Jiang, J. Singh, K. Kamath, and P. Bhattacharya, Phys. Rev. B 57, R9423 (1998); T. Mu¨ller, F. F. Schrey, G. Strasser, and K. Unterrainer, Appl. Phys. Lett. 83, 3572 (2003); M. De Giorgi, C. Lingk, G. von Plessen, J. Feldmann, S. De Rinaldis, A. Passaseo, M. De Vittorio, R. Cingolani, and M. Lomascolo, Appl. Phys. Lett. 79, 3968 (2001); T. F. Boggess, L. Zhang, D. G. Deppe, D. L. Huffaker, and C. Cao, Appl. Phys. Lett. 78, 276 (2001).
    • [24] A. L. Efros, V. A. Kharchenko, and M. Rosen, Solid State Commun. 93, 281 (1995).
    • [25] L.-W. Wang, M. Califano, A. Zunger, and A. Franceschetti, Phys. Rev. Lett. 91, 056404 (2003).
    • [26] P. Guyot-Sionnest, B. Wehrenberg, and D. Yu, J. Chem. Phys. 123, 074709 (2005).
    • [27] M. Califano, J. Phys. Chem. C (in press).
    • [28] J. M. Harbold, H. Du, T. D. Krauss, K.-S. Cho, C. B. Murray, and F. W. Wise, Phys. Rev. B 72, 195312 (2005).
    • [29] R. D. Schaller and V. I. Klimov, Phys. Rev. Lett. 92, 1886601 (2004).
    • [30] R. J. Ellingson, M. C. Beard, J. C. Johnson, P. Yu, O. I. Micic, A. J. Nozik, A. Shabaev, and A. L. Efros, Nano Letters 5, 865 (2005).
    • [31] J.M. Harbold and F.W. Wise, Phys. Rev. B 76, 125304 (2007).
    • [32] I. Kang and F. W. Wise, J. Opt. Soc. Am. B 14, 1632 (1997).
    • [33] C. Bonati, A. Cannizzo, D. Tonti, A. Tortschanoff, F. van Mourik, and M. Chergui, Phys. Rev. B 76, 033304 (2007).
    • [34] R. D. Schaller, M. A. Petruska, and V. I. Klimov, Appl. Phys. Lett. 87, 253102 (2005).
    • [35] J. E. Murphy, M. C. Beard, A. G. Norman, S. P. Ahrenkiel, J. C. Johnson, P. Yu, O. I. Micic, R. J. Ellingson, and A. J. Nozik, J. Am. Chem. Soc. 128, 3241 (2006).
    • [36] S. H. Wei and A. Zunger, Phys. Rev. B 55, 13605 (1997).
    • [37] PbSe does have different properties relative to ordinary II-VI materials, e.g., its dielectric constant is 22.9, while the dielectric constant of CdSe is 6.3. However, this leads to only quantitative differences in carrier decay, not qualitative differences.
    • [38] V. Klimov, J. Phys. Chem. B 104, 6112 (2000).
    • [39] G. Allan and C. Delerue, Phys. Rev. B 70, 245321 (2004).
    • [40] X. Cartoix`a and L.-W. Wang, Phys. Rev. Lett. 94, 236804 (2005).
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article