Code: MOC	Time Slot/Poster Number: 10:30 - 11:00 am	Session: Solid State, Semiconductors and Nanoparticles I
Raman Spectroscopy and Translation Symmetry of Nanocrystalline Structures
Shu-Lin Zhang
Peking University, Beijing, China
View Abstract PDF
Summary
An introduction to history and the newest progress of the Raman spectroscopic studies of NC-structures, mainly, NC-semiconductors are given. The crystalline and amorphous Raman features, as well as, do and no diameter-selective Raman scattering were observed respectively in the optical phonons of non-polar and polar nano-crystalline semiconductors. These novel features were attributed to the difference between the electron-phonon interactions of optical phonons in non-polar and polar semiconductors. The results and interpretation shed a light on an important nature of NC-structures that the size-scale of the breaking of translation symmetry is not fixed and dependent of related interaction property.

Code: MOC	Time Slot/Poster Number: 11:00 - 11:30 am	Session: Solid State, Semiconductors and Nanoparticles I
Raman Scattering from Industrially Prepared Nanometer Sized Particles of Monoclinic and Cubic Phases of Yttrium Europium Oxide Phosphors
Robert Withnall1; Terry Ireland1; Jack Silver1; George Fern1; Alastair Godfrey2; Paul Reip2
1Brunel University, Uxbridge, United Kingdom; 2Intrinsiq Materials, Farnborough, UK
View Abstract PDF
Summary
Nanometer sized crystals of Y2O3:Eu were synthesized by passing precursor phosphor powders through a plasma discharge at ca. 9000°C by Intrinsiq Materials Ltd. The as-prepared crystals were found to be monoclinic Y2O3:Eu using powder X-ray diffraction. However, the Raman spectra provided evidence that these crystals could be converted to the cubic phase by annealing in the 400-900°C temperature range for one hour.

Code: MOC	Time Slot/Poster Number: 11:30 - 11:50 am	Session: Solid State, Semiconductors and Nanoparticles I
Semiconductor Nanoparticles for Photovoltaics
Justin Habinshuti1, 2; Sylvia Turrell1; Christophe Kinowski3; Didier Stievenard2; Tao Xu2; Bruno Grandidier2; Odile Cristini3
1LASIR, Villeneuve D'ascq, France; 2IEMN, Departement ISEN, 41 Bd Vauban, Lille, France; 3PhLAM, Université de Lille 1, Villeneuve d'Ascq, France
View Abstract PDF
Summary
In a study devoted to the development of a new photovoltaic scheme, Si nanowires have been combined with semiconductor nanoparticles (NP) in order to increase conversion efficiency. Nanoparticles were prepared using colloidal syntheses and drop casting techniques. Encasing zircon matrices were developped using sol-gel techniques. Micro Raman spectroscopic results have been correlated with data obtained by UV-visible absorption and emission spectroscopies as well as SEM measurements to follow the effect of synthesis parameters (temperature, solvents...) on the NP size and size distribution, as well as the interactions between NPs and the Zr matrix.

Code: MOC	Time Slot/Poster Number: 11:50 am - 12:10 pm	Session: Solid State, Semiconductors and Nanoparticles I
Enhanced Raman Scattering of Silicon Nanowires by Ag Nanoparticles in-situ Decoration
Zeping Peng1; Hailong Hu1; Shijie Wang2; Zexiang Shen1; Qihua Xiong1
1Nanyang Technological University, Singapore, Singapore; 2Institute of Materials Research and Engineering, Singapore, Singapore
View Abstract PDF
Summary
Recently metallic nanoparticles decorated semiconductor nanowires attract considerable attention due to their potential applications in photocatalysis, photovoltaics and surface enhanced Raman scattering. Here we report a method to decorate silicon nanowires with Ag nanoparticles by surface reduction, in which a freshly etched silicon surface reduces Ag ions in-situ in aqueous solution. The as-grown Ag nanoparticles exhibit either single crystallinity or twinning boundaries. Raman mapping suggested a substantially enhanced scattering due to Ag decoration. This was explained by local electric field enhancement due to nano-antenna effect, which was supported by the correlation between atomic force microscopy analysis and Raman mapping.

Code: MOC	Time Slot/Poster Number: 12:10 - 12:30 pm	Session: Solid State, Semiconductors and Nanoparticles I
Raman Spectroscopy for Demonstrating the Sub-Wavelength Light Transmission
Chang Chen1; Ronald Kox1; Francesca Clemente1; Liesbet Lagae1; Guido Maes2; Gustaaf Borghs1; Pol Van Dorpe1
1Imec VZW, Leuven, Belgium; 2Katholieke Universiteit Leuven, Leuven, Belgium
View Abstract PDF
Summary
Extraordinary optical transmission (EOT) through sub-wavelength nanoholes or nanoslits supplies plenty of fascinating applications in photon manipulations and molecular spectroscopies. In this work, we show both experimentally and numerically that how Raman spectroscopy can be used to demonstrate the sub-wavelength light transmission through a 15 nm nanoslit. Furthermore the polarization dependence of the Raman spectra from slits of different sizes is also investigated. This Raman photon transmission phenomenon is expected to open up new prospects for near-field Raman spectroscopy and sub-wavelength measurements.