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Transversal confined polar optical phonons in spherical quantum‐dot/quantum‐well nanostructures
Author(s) -
Comas F.,
TralleroGiner C.,
Prado S. J.,
Marques G. E.,
Roca E.
Publication year - 2006
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200541326
Subject(s) - phonon , nanostructure , quantum dot , condensed matter physics , brillouin zone , polar , dielectric , quantum , physics , materials science , optoelectronics , quantum mechanics
Confined polar optical phonons are studied in a spherical quantum‐dot/quantum‐well (QD/QW) nanostructure by using an approach that takes into account the coupling of electromechanical oscillations and is valid in the long‐wave limit. This approach was developed a few years ago and provides results beyond the usually applied dielectric continuum approach (DCA), where just the electric aspect of the oscillations is considered. In the present paper we limit ourselves to the study of the so‐called uncoupled modes, having a purely transversal character and not involving an electric potential. We display the dispersion curves for the frequencies considering three possible nanostructures, which show different bulk phonon curvatures near the Brillouin zone Γ‐point and have been actually grown: ZnS/CdSe, CdSe/CdS and CdS/HgS. A detailed discussion of the results obtained is made, emphasizing the novelties provided by our treatment and the relevance of infrared spectroscopy in the characterization of the geometrical features of the QD/QW nanostructure. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)