Size and structure dependent ultrafast dynamics of plasmonic gold nanosphere heterostructures on poly (ethylene glycol) brushes
Journal article, 2017

We have investigated the plasmonic properties of heterostructures that consist of gold nanosphere (NSs) with average diameters of 60 nm, 40 nm and 20 nm on poly (ethylene glycol) (PEG) brushes by using ultrafast pump-probe spectroscopy experiments. Gold NSs start to behave like gold nanorods with increasing number of immobilization cycles due to the close proximity. Gold NSs immobilized by 3 and 5 deposition cycles show longitudinal modes of plasmon bands at long wavelengths which are characteristic behaviors for gold nanorods. Increasing the number of immobilization cycle also increase relaxation times of samples due to the close proximity. Linear absorption spectra and scanning electron microscopy images show that there are close packing assemblies for heterostructures containing 20 nm gold NSs as the small particle. Ultrafast electron transfer (<100 fs) occurs between transverse and longitudinal modes by exciting the samples at both 520 nm and 650 nm. Further, experimental results indicate that, heterostructures with the small particles have faster relaxation times than other heterostructures due to closed packing of 20 nm gold NSs. (C) 2017 Elsevier B.V. All rights reserved.

absorption

nanostructures

Ultrafast dynamics

optical-properties

arrays

Plasmonics

Materials Science

shape

nanorods

metal nanoparticles

Heterostructures

electron

Optics

Ultrafast

Gold nanospheres

Polymer brushes

dynamics

colloidal gold

spectroscopy

Author

A. Karatay

Ankara Universitesi

Betül Kücüköz

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Physical Chemistry

S. Pekdemir

Erciyes Universitesi

M. S. Onses

Erciyes Universitesi

A. Elmali

Ankara Universitesi

Optical Materials

0925-3467 (ISSN)

Vol. 73 NOV 83-88

Driving Forces

Sustainable development

Subject Categories

Chemical Process Engineering

Chemical Sciences

Roots

Basic sciences

DOI

10.1016/j.optmat.2017.08.008

More information

Created

12/13/2017