Effects of shape on the optical properties of CdSe@Au core-shell nanocomposites

We studied the local field enhancement factor (LFEF), absorption, and extinction cross sections of spherical, cylindrical, oblate, and prolate core–shell nanocomposites (NCs) theoretically and numerically using the quasi-static approach. By solving Laplace’s equations, we obtained expressions for th...

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Main Authors: Garoma Dhaba Bergaga, Belayneh Mesfin Ali, Teshome Senbeta Debela
Format: Article
Language:English
Published: AIP Publishing LLC 2023-03-01
Series:AIP Advances
Online Access:http://dx.doi.org/10.1063/5.0138456
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author Garoma Dhaba Bergaga
Belayneh Mesfin Ali
Teshome Senbeta Debela
author_facet Garoma Dhaba Bergaga
Belayneh Mesfin Ali
Teshome Senbeta Debela
author_sort Garoma Dhaba Bergaga
collection DOAJ
description We studied the local field enhancement factor (LFEF), absorption, and extinction cross sections of spherical, cylindrical, oblate, and prolate core–shell nanocomposites (NCs) theoretically and numerically using the quasi-static approach. By solving Laplace’s equations, we obtained expressions for the LFEF, polarizability, absorption, and scattering cross sections for each of the core–shell NCs. We found that the LFEF, absorption, and extinction cross section of spherical and cylindrical core–shell NCs possess two peaks whereas oblate and prolate spheroids show three observable peaks. Moreover, the prolate core–shell spheroid shows greater tunability and larger intensity of the LFEF than its corresponding oblate structure. Furthermore, spherical nanoshells are characterized by the higher LFEF than cylindrical and spheroidal core–shells of the same size and composition. When compared, even the smallest value of the LFEF of the spherical core–shell is 11.42 and 10.09 times larger than the biggest values of oblate and prolate core-shells, respectively. The study also indicated that for spherical and cylindrical NCs, the first two peaks of the LFEF and extinction cross sections are achieved at the same corresponding frequencies. Furthermore, all peaks of the extinction cross sections of the prolate spheroid are found to be the lowest while those of the cylindrical peaks are the highest. Where there are an equal number of peaks of different shapes, the peak values are different, showing that shapes of core–shell NCs determine the intensity, the number, and the positions of peaks of the LFEF and optical cross sections. Such NCs are promising for applications in optical sensing, bio-sensing, and electronic devices. Especially, gold coated core–shell spheroids have good potential applications in multi-channel sensing.
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spelling doaj.art-2c586d800be44d9685887cd59542bcad2023-07-26T14:03:59ZengAIP Publishing LLCAIP Advances2158-32262023-03-01133035331035331-1010.1063/5.0138456Effects of shape on the optical properties of CdSe@Au core-shell nanocompositesGaroma Dhaba Bergaga0Belayneh Mesfin Ali1Teshome Senbeta Debela2Department of Physics, Addis Ababa University, P.O. Box: 1176, Addis Ababa, EthiopiaDepartment of Physics, Addis Ababa University, P.O. Box: 1176, Addis Ababa, EthiopiaDepartment of Physics, Addis Ababa University, P.O. Box: 1176, Addis Ababa, EthiopiaWe studied the local field enhancement factor (LFEF), absorption, and extinction cross sections of spherical, cylindrical, oblate, and prolate core–shell nanocomposites (NCs) theoretically and numerically using the quasi-static approach. By solving Laplace’s equations, we obtained expressions for the LFEF, polarizability, absorption, and scattering cross sections for each of the core–shell NCs. We found that the LFEF, absorption, and extinction cross section of spherical and cylindrical core–shell NCs possess two peaks whereas oblate and prolate spheroids show three observable peaks. Moreover, the prolate core–shell spheroid shows greater tunability and larger intensity of the LFEF than its corresponding oblate structure. Furthermore, spherical nanoshells are characterized by the higher LFEF than cylindrical and spheroidal core–shells of the same size and composition. When compared, even the smallest value of the LFEF of the spherical core–shell is 11.42 and 10.09 times larger than the biggest values of oblate and prolate core-shells, respectively. The study also indicated that for spherical and cylindrical NCs, the first two peaks of the LFEF and extinction cross sections are achieved at the same corresponding frequencies. Furthermore, all peaks of the extinction cross sections of the prolate spheroid are found to be the lowest while those of the cylindrical peaks are the highest. Where there are an equal number of peaks of different shapes, the peak values are different, showing that shapes of core–shell NCs determine the intensity, the number, and the positions of peaks of the LFEF and optical cross sections. Such NCs are promising for applications in optical sensing, bio-sensing, and electronic devices. Especially, gold coated core–shell spheroids have good potential applications in multi-channel sensing.http://dx.doi.org/10.1063/5.0138456
spellingShingle Garoma Dhaba Bergaga
Belayneh Mesfin Ali
Teshome Senbeta Debela
Effects of shape on the optical properties of CdSe@Au core-shell nanocomposites
AIP Advances
title Effects of shape on the optical properties of CdSe@Au core-shell nanocomposites
title_full Effects of shape on the optical properties of CdSe@Au core-shell nanocomposites
title_fullStr Effects of shape on the optical properties of CdSe@Au core-shell nanocomposites
title_full_unstemmed Effects of shape on the optical properties of CdSe@Au core-shell nanocomposites
title_short Effects of shape on the optical properties of CdSe@Au core-shell nanocomposites
title_sort effects of shape on the optical properties of cdse au core shell nanocomposites
url http://dx.doi.org/10.1063/5.0138456
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