title: Exciton lifetime tuning by changing the plasmon field orientation with respect to the exciton transition moment direction: CdTe-Au core-shell nanorods.
abstract: We studied the anisotropy of the influence of plasmonic fields, arising from the optical excitation of a gold nanoshell plasmon absorption at 770 nm, on the lifetime of the bandgap state of the CdTe core in vertically aligned CdTe-Au core-shell nanorods. The previously observed decrease in the lifetime was studied as a function of the tilt angle between the long axis of the nanorod and the electric field polarization direction of the plasmon inducing exciting light. It is observed that the strongest enhancement to the exciton relaxation rate occurs when the two axes are parallel to one another. These results are discussed in terms of the coupling between the exciton transition moment of the CdTe rod and the electric field polarization direction of the gold nanoshell plasmon at 770 nm, which was determined from theoretical modeling based on the discrete dipole approximation.
authors.affiliation: Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Neretina
authors.forename: Wei
authors.initials: W
authors.lastname: Qian
authors.forename: Erik C
authors.initials: EC
authors.lastname: Dreaden
authors.forename: Mostafa A
authors.initials: MA
authors.lastname: El-Sayed
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hughes
authors.forename: John S
authors.initials: JS
authors.lastname: Preston
authors.forename: Peter
authors.initials: P
authors.lastname: Mascher
mesh_terms: D002104:Cadmium / Q000737:chemistry*; D019187:Cadmium Compounds; D003198:Computer Simulation; D006046:Gold / Q000737:chemistry*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D008962:Models, Theoretical; D036103:Nanotechnology / Q000379:methods*; D053770:Nanowires / Q000737:chemistry*; D012666:Semiconductors; D013691:Tellurium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D002104:Cadmium; D006046:Gold; D013691:Tellurium; C028337:cadmium telluride