1. A. Abdi, L.V. TitovaL. M. Smith and H. E. Jackson A. Abdi, L.V. Titova, L. M. Smith and H. E. Jackson Department of Physics, University of Cincinnati, Ohio 45221-0011 J. M. Yarrison-Rice Department of Physics, Miami University, Oxford, OH J. L. Lensch * and L. J. Lauhon Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208 Supported by NSF and partially supported by the Petroleum Research Fund of the American Chemical Society and Northwestern University and a * National Science Foundation Graduate Research Fellowship. Probing the Electronic and Vibronic Structure of Single and Ensemble CdS Nanowires using Resonant Raman Scattering

2. Outline …  Sample preparation  An ensemble of CdS nanowires  Resonant Raman Scattering  Single CdS nanowire  Resonant Raman Scattering  Summary

3. VLS Sample Growth Alloy Liquid Vapor CdS Nanowire Au Catalysts Si Substrate Y. Wu and P. Yang, J. Am. Chem. Soc. 123, 3165 (2001)

4. SEM of CdS Nanowires 1  m An ensemble with an average diameter of 10 nm

5. Resonant Raman Spectrum at Room Temperature for a CdS Nanowire Ensemble

6. Background Subtracted Resonant Raman Scattering

7. 1 LO Resonance Raman Intensities vs. Excitation Energy for CdS Nanowire Ensemble

8. Resonant Raman Intensity vs. Energyfor CdS Nanowire Ensemble Resonant Raman Intensity vs. Energy for CdS Nanowire Ensemble

9. Outline …  Sample preparation  An ensemble of CdS nanowires  Resonant Raman Scattering  Single CdS nanowire  Resonant Raman Scattering  Summary

10. Single (10 nm catalyst) CdS Nanaowire

11. Resonance Raman Intensities vs. Excitation Energy of a Single CdS Nanowire

12. Summary RRS has been used to study successfully both an ensemble and a single of CdS nanowires at room temperature. The similarity of the lineshapes of the PL and the RRS integrated intensities indicates that we probe the electronic states. 1 LO and 2 LO Energy differences are consistent with the bulk CdS values.