Plasmonic Absorption Enhancement in Au/CdS Nanocomposite

Authors: K. Easawi, M. Nabil, T. Abdallah, S. Negm, H. Talaat

Abstract:

Composite nanostructures of metal core/semiconductor shell (Au/CdS) configuration were prepared using organometalic method. UV-Vis spectra for the Au/CdS colloids show initially two well separated bands, corresponding to surface plasmon of the Au core, and the exciton of CdS shell. The absorption of CdS shell is enhanced, while the Au plasmon band is suppressed as the shell thickness increases. The shell sizes were estimated from the optical spectra using the effective mass approximation model (EMA), and compared to the sizes of the Au core and CdS shell measured by high resolution transmission electron microscope (HRTEM). The changes in the absorption features are discussed in terms of gradual increase in the coupling strength of the Au core surface plasmon and the exciton in the CdS. leading to charge transfer and modification of electron oscillation in Au core.

Keywords: Nanocomposites, Plasmonics.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1073140

References:

[1] Zhang, J. Tang, Y, Lee, K, Ouyang, M. Science 2010, 327, 1634-1638.
[2] Shi, W. L, Zeng, H., Sahoo, Y., Ohulchannnnskyy, T. Y., Ding, Y., Wang, Z. L., Swihart, M., Prasad, P. N. Nano lett. 2006, 6, 875.
[3] Kim, H, Achermann, M, Balet, L. P, Hollingsworth, J.A, Klimov, V.I. J. am. Chem, Soc 005, 127, 544-546.
[4] Marc Achermann. phys.chem.lett.2010,1,2837-2843
[5] C. Zhong, M. M.Maye, Adv. Mater. 13 (2001) 1507
[6] Morfa, A. J. Rowlen, K, L, Reilly, T.H. Romero, M.J. Van delagemaat, J. Appl. Phys.lett. 2008, 92,No.013504
[7] Oulton, R. F, Sorger, V. J. Zentttttgraf, T, Ma, R. M, Gladden, C, Dai, L, Bartal, G, Zhang Nature 2009,461,629-632.
[8] Jestle, M, Maran, I, Kock, A, Beinsting, W, Gornik, E, Opt, Lett.1989, 14, 719-721.
[9] Yanfei Wang, Minjie Li, Spectrochimic ta Part a Ac A 64 (2006) 101- 105.
[10] W. William Yu, Lianhua Qu, Wenzhuo, Guo, and xiaogang Peng, ChemMater, 2003, 15, 2854-2860.
[11] Prashant V. Kamat and Bhairavi shanghavi, Phys. Chem B. 1997,101, 7675-7679.
[12] Elena Khon, Andrey Mereshchenko, Alexander N. Tarnovsky, Krishna Acharya, Anna Klinkova, Nishshanka N. Hewa-Kasakarage, Ian Nemitz, and Mikhail Zamkov, Nano Letter, 2011, 11, 1792-1799.