Probing the structure of core-shell nanoparticles by resonant Raman scattering spectroscopy

Volodymyr Dzhagan 1Mykhailo Valakh 1Olexandra Rayevskaya 2Alexander L. Stroyuk 2Stepan Kuchmiy 2Dietrich RT Zahn 3

1. Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Prospect Nauki,45, Kyiv 03028, Ukraine
2. Institute of Physical chemistry of NAS of Ukraine (IFH), Nauky pr., 31, Kyiv 03028, Ukraine
3. Chemnitz University of Technology, Semiconductor Physics, Chemnitz D-09107, Germany

Abstract

Semiconductor nanoparticles of high structural and optical quality can be now produced in application-sufficient quantities. For a thorough understanding and precise manipulation of properties of composite (hetero-)nanoparticles, the knowledge about their interface structure is needed. A combination of resonant Raman scattering (RRS) with photoluminescence (PL) and optical absorption gives information on the surface and interface structure of heteronanoparticles, supplementary to X-ray, photoelectron spectroscopy and TEM. In the present report a complex effect of the confinement, strain, interdiffusion and distribution of the NP sizes within the ensemble onto the RRS spectra on optical phonons is investigated. In particular, the advantages and shortcomings of the size-selectivity of the resonant Raman scattering from the NP ensembles are discussed. A possibility to assess the interdiffusion extent and residual strain value at the interface of colloidal CdSe/MS (M=Zn, Cd, Pb, Ni, Mn) core-shell NPs from the resonant Raman spectra is demonstrated. CdSe NPs passivated with selenides - HgSe, Ag2Se, CuSe, Bi2Se3 - have not revealed any shell-related phonon bands or shifts of the core phonon peak. The dependence of the surface phonon parameters on the passivating shell type and effective thickness is analyzed.

 

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Presentation: Poster at E-MRS Fall Meeting 2008, Symposium J, by Volodymyr Dzhagan
See On-line Journal of E-MRS Fall Meeting 2008

Submitted: 2008-06-18 14:20
Revised:   2009-06-07 00:48