Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-27T02:12:21.938Z Has data issue: false hasContentIssue false
  • English
  • Français

Phase-separation in ZnxCd1-xSe/C Core/shell nanocrystals studied with cathodoluminescence spectroscopy

Published online by Cambridge University Press:  01 February 2011

Yevgeni Estrin ,
Daniel H Rich ,
Ofer Moshe ,
Sayan Bhattacharyya  and
Aharon Gedanken
Yevgeni Estrin
Affiliation:
[email protected], Ben-Gurion University of the Negev, Department of Physics, Beer-Sheva, Israel
Daniel H Rich
Affiliation:
[email protected], Ben-Gurion University of the Negev, Department of Physics, Beer-Sheva, Israel
Ofer Moshe
Affiliation:
[email protected], Ben-Gurion University of the Negev, Department of Physics, Beer-Sheva, Israel
Sayan Bhattacharyya
Affiliation:
[email protected], Bar-Ilan University, Department of Chemistry, Ramat-Gan, Israel
Aharon Gedanken
Affiliation:
[email protected], Bar-Ilan University, Department of Chemistry, Ramat-Gan, Israel
Get access

Abstract

ZnxCd1-xSe/C core/shellnanocrystals with 31-39 nm diameter semiconductor cores and 11-25 nm-thick carbon shells were synthesized from solid state precursors. Transmission electron microscopy showed striations on a scale of ˜1 – 5 nm in the nanocrystals that are indicative of a composition modulation, and reveal a chemical phase separation and possible spinodal decomposition within the nanocrystals. Such a composition modulation within the ternary nanocrystals represents a rarely reported phenomenon that could lead to additional applications. The optical properties and carrier relaxation kinetics of the nanocrystals were examined with variable excitation cathodoluminescence (CL). As the excitation level is increased, carrier filling in two-dimensional (2D) phase-separated Cd-rich regions leads to a partial saturation of states before the onset of carrier filling in the higher bandgap homogenous Zn0.47Cd0.53Se regions. In order to model the state filling using Fermi-Dirac statistics for non-interacting carriers, a random quantum well model was used to determine the electron and hole eigensates in the Cd-rich regions of the nanocrystals.

Keywords

nanostructureoptical propertiesluminescence
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1260: Symposium T – Photovoltaics and Optoelectronics from Nanoparticles , 2010 , 1260-T10-03
Copyright
Copyright © Materials Research Society 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Zhang, X. T., Liu, Z., Li, Q., Hark, S. K., J. Phys. Chem. B 109, 17913 (2005).Google Scholar
2 Lee, H. et. al., J. Chem. Phys. 125, 164711 (2006).Google Scholar
3 Sung, Y.-M., Lee, Y.-J., and Park, K.-S., J. Am. Chem. Soc. 128, 9002 (2006).Google Scholar
4 Zhang, B. P., Li, Y. Q., Yasuda, T., Wang, W. X., Segawa, Y., Edamatsu, K. and Itoh, T., Appl. Phys. Lett. 73, 1266 (1998).Google Scholar
5 Kim, J. I. and Lee, J.-K., Adv. Funct. Mater. 16, 2077 (2006).Google Scholar
6 Zheng, Y., Yang, Z. and Ying, J. Y., Adv. Mater. 19, 1475 (2007).Google Scholar
7 Hsieh, K. C., Baillargeon, J. N., and Cheng, K. Y., Appl. Phys. Lett. 57, 2244 (1990).Google Scholar
8 Mascarenhas, A., Alonso, R. G., Horner, G. S., Froyen, S., Hsieh, K. C., and Cheng, K. Y., Phys. Rev. B 48, 4907 (1993).Google Scholar
9 Tang, Y., Rich, D. H., Moy, A. M. and Cheng, K. Y., J. Vac. Sci. Technol. B 15, 1034 (1997).Google Scholar
10 Marbeuf, A. , Druilhe, R., Triboulet, R., Patriarche, G., J. Cryst. Growth 117, 10 (1992).Google Scholar
11 Lee, H. S. et. al. al., J. Appl. Phys. 99, 093512 (2006).Google Scholar
12 Zhang, X. B. and Hark, S. K., J. Cryst. Growth 223, 512 (2001).Google Scholar
13 Bhattacharyya, S., Estrin, Y., Moshe, O., Rich, D. H., Solovyov, L. A., and Gedanken, A., ACS Nano 3, 1864 (2009).Google Scholar
14 Estrin, Y., Rich, D. H., Moshe, O., Bhattacharyya, S. and Gedanken, A., Appl. Phys. Lett. 95, 181903 (2009).Google Scholar
15 Lin, H. T., Rich, D. H., Konkar, A., Chen, P., and Madhukar, A., J. Appl. Phys. 81, 3186 (1997).Google Scholar
16 Kolbas, R. M. and Holonyak, N., Am. J. Phys. 52, 431 (1984).Google Scholar
17 Müller, J. et et. al. Nano Lett. 5, 2044 (2005).Google Scholar
18 Targer-Cowan, C. et. al. Semicond. Sci. Technol. 7, 536 (1992).Google Scholar
19 Maksimov, M. V., Krestnikov, I. L., Ivanov, S. V., Ledentsov, N. N., and Sorokin, S. V., Semiconductors 31, 800 (1997).Google Scholar