Polar optical phonons in semiconducting CdS nanocrystals
- Moscow State University, Department of Physics (Russian Federation)
- Universidade do Minho, Centro de Fisica (Portugal)
- Technical University, Moscow Institute of Electronic Technology (Russian Federation)
We have experimentally and theoretically studied IR-active optical phonons, which are spatially confined in the volume of semiconducting CdS nanocrystals of various shapes synthesized in a dielectric matrix (porous aluminum oxide). Within an approach admitting the mixing of all expected types of vibrations, the complete sets of phonon modes are determined for a spherical quantum dot (QD) and a cylindrical quantum wire (QW) in this matrix. Based on these results, the polarizability spectra of QDs and QWs, as well as the effective dielectric function of a composite material containing such nanoparticles, are calculated for the far-IR wavelength range. It is established that the spectrum of the dielectric function exhibits specific features in the region between the transverse and longitudinal optical phonon frequencies of the massive semiconductor material. These features explain the rather unusual structure of the IR spectra of the composite samples studied.
- OSTI ID:
- 21072547
- Journal Information:
- Journal of Experimental and Theoretical Physics, Vol. 104, Issue 1; Other Information: DOI: 10.1134/S1063776107010128; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
- Country of Publication:
- United States
- Language:
- English
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