Near-field Raman dichroism of azo-polymers exposed to nanoscale dc electrical and optical poling
File(s)c6nr07508h.pdf (2.87 MB)
Published version
Author(s)
Kharintsev, Sergey S
Fishman, Alexandr I
Saikin, Semion K
Kazarian, Sergei G
Type
Journal Article
Abstract
Azobenzene-functionalized polymer films are functional materials, where the (planar vs. homeotropic) orientation of azo-dyes can be used for storing data. In order to characterize the nanoscale 3D orientation of the pigments in sub-10 nm thick polymer films we use two complementary techniques: polarization-controlled tip-enhanced Raman scattering (TERS) microscopy and contact scanning capacity microscopy. We demonstrate that the homeotropic and planar orientations of the azo-dyes are produced by applying a local dc electrical field and a resonant longitudinal optical near-field, respectively. For a non-destructive probe of the azo-dye orientation we apply a non-resonant optical near-field and compare the intensities of the Raman-active vibrational modes. We show that near-field Raman dichroism, a characteristic similar to the absorption dichroism used in far-field optics, can be a quantitative indicator of the 3D molecular orientation of the azo-dye at the nanoscale. This study directly benefits the further development of photochromic near-field optical memory that can lead to ultrahigh density information storage.
Date Issued
2016-12-21
Date Acceptance
2016-11-04
Citation
Nanoscale, 2016, 8 (47), pp.19867-19875
ISSN
2040-3364
Publisher
Royal Society of Chemistry
Start Page
19867
End Page
19875
Journal / Book Title
Nanoscale
Volume
8
Issue
47
Copyright Statement
This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
License URL
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Multidisciplinary
Nanoscience & Nanotechnology
Materials Science, Multidisciplinary
Physics, Applied
Chemistry
Science & Technology - Other Topics
Materials Science
Physics
THIN-FILMS
POLARIZATION MEASUREMENTS
FUNCTIONALIZED POLYMERS
LONGITUDINAL-FIELD
SPECTROSCOPY
STORAGE
ANISOTROPY
DESIGN
DIPOLE
DYE
Publication Status
Published
Date Publish Online
2016-11-07