21 / 28
Page 52
allied
academies
Journal of Materials Science and Nanotechnology | Volume: 2
August 20-21, 2018 | Paris, France
Materials Science and Materials Chemistry
International Conference on
Discrete dipole approximation to determine the optical properties of ZnO polymer nanocomposite
Sachindranath Das, Subhasish Patra
and
Payal Sengupta
Jadavpur University, India
O
ptical properties have been simulated by DDA for ZnO NPs
and ZnO-PVP composite for different particle size with
complex dielectric function as input. The absorption efficiency
factor for ZnO NPs of size 26 nm and that for ZnO-PVP of size
28 nm in simulation matches well with the experimentally
obtained absorbance data. When ZnO is simulated for the
particle size of 26 nm, the electric near-field intensities on
the edges show fewer intensities compared with the center.
The simulation of ZnO-PVP composites of 28 nm results in a
spherical electric near-field with a larger diameter. Since ZnO
is a hexagonal structure, the near-field appears to be most
intense at the center followed by the edges of the NP. The
increase of near electric field due to the presence of local
dielectric medium may be the possible reason to behave a
particle within the dielectric medium as the particle with higher
effective radius. So, in ZnO-PVP composite, ZnO NPs act as a
particle with higher effective radius. As a result, in presence
of dielectric medium, the absorbance peak of same NPs shifts
towards higher wavelength. The dielectric medium perturbs
electron-phonon interaction as well as the optoelectronic
properties. Moreover, the luminescence properties of the
materials are affected due to composite formation. In case
of NP-polymer composite, NPs are capped and there is
negligible further adsorption and desorption of O
2
molecules
occurred on the surface. This increases the photocurrent
as well as photosensitivity, which makes the ZnO-PVP
composite as a suitable candidate for visible-blind UV detector.
e:
sachindran.das@jadavpuruniversity.in