Open AccessLocal field-induced optical properties of Ag-coated CdS quantum dots
Author(s) -
Koo–Chul Je,
Honglyoul Ju,
Mona Tréguer,
Thierry Cardinal,
Seung Han Park
Publication year - 2006
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.14.007994
Subject(s) - quantum dot , exciton , stark effect , local field , condensed matter physics , hamiltonian (control theory) , materials science , quantum confined stark effect , biexciton , effective mass (spring–mass system) , physics , molecular physics , electric field , optoelectronics , quantum mechanics , mathematical optimization , mathematics
Local field-induced optical properties of Ag-coated CdS quantum dot structures are investigated. We experimentally observe a clear exciton peak due to the quantum confinement effect in uncoated CdS quantum dots, and surface plasmon resonance and red-shifted exciton peak in Ag-coated CdS composite quantum dot structures. We have calculated the Stark shift of the exciton peak as a function of the local field for different silver thicknesses and various sizes of quantum dots based on the effective-mass Hamiltonian using the numerical-matrix-diagonalization method. Our theoretical calculations strongly indicate that the exciton peak is red-shifted in the metal-semiconductor composite quantum dots due to a strong local field, i.e., the quantum confined Stark effect.