Optical and structural studies of phase separation in Zn xCd 1-xSe/C core/shell nanocrystals

D. H. Rich, Y. Estrin, O. Moshe, Sayan Bhattacharyya, A. Gedanken

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

Zn xCd 1-xSe/C core/shell nanocrystals with 31-39 nm diameter semiconductor cores and 11-25 nm-thick carbon shells were synthesized from solid state precursors in large scale amounts. Transmission electron microscopy (TEM) showed striations in the nanocrystals that are indicative of a composition modulation, and reveal a chemical phase separation and possible spinodal decomposition within the nanocrystals. The optical properties and carrier relaxation kinetics of the nanocrystals were examined with cathodoluminescence (CL) imaging and spectroscopy. As the excitation level is increased, carrier filling in two-dimensional phase-separated Cd-rich regions leads to a partial saturation of states before the onset of carrier filling in the higher bandgap homogenous Zn 0.47Cd 0.53Se regions. In order to model the state filling and calculate quasi-Fermi levels for electrons and holes, a random quantum well model was used to determine the electron and hole eigensates in the Cd-rich regions of the nanocrystals.

Original languageEnglish
Title of host publicationPhysics of Semiconductors - 30th International Conference on the Physics of Semiconductors, ICPS-30
Pages219-220
Number of pages2
DOIs
StatePublished - 1 Dec 2011
Event30th International Conference on the Physics of Semiconductors, ICPS-30 - Seoul, Korea, Republic of
Duration: 25 Jul 201030 Jul 2010

Publication series

NameAIP Conference Proceedings
Volume1399
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Conference

Conference30th International Conference on the Physics of Semiconductors, ICPS-30
Country/TerritoryKorea, Republic of
CitySeoul
Period25/07/1030/07/10

Keywords

  • CdSe
  • ZnSe
  • cathodoluminescence
  • nanocrystals
  • transmission electron microscopy

ASJC Scopus subject areas

  • General Physics and Astronomy

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