Fluorescence signals of core-shell quantum dots enhanced by single crystalline gold caps on silicon nanowires.
We use nanoscale (20-300 nm in diameter) single crystalline gold (Au)-caps on silicon nanowires (NWs) grown by the vapor-liquid-solid (VLS) growth mechanism to enhance the fluorescence photoluminescence (PL) signals of highly dilute core/shell CdSeTe/ZnS quantum dots (QDs) in aqueous solution (10(-5) M). For NWs without Au-caps, as they appear, for example, after Au etching in aqua regia or buffered KI/I(2)-solution, essentially no fluorescence signal of the same diluted QDs could be observed. Fluorescence PL signals were measured using excitation with a laser wavelength of 633 nm. The signal enhancement by single crystalline, nanoscale Au-caps is discussed and interpreted based on finite element modeling (FEM).
Max-Planck-Institute of Microstructure Physics, Weinberg 2, D-06120 Halle, Germany. Institute of Photonic Technology (IPHT), Albert-Einstein-Strasse 9, D-07745 Jena, Germany.
S H
SH
Christiansen
J W
JW
Chou
M
M
Becker
V
V
Sivakov
K
K
Ehrhold
A
A
Berger
W C
WC
Chou
D S
DS
Chuu
U
U
Gösele