Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods

We report on the dynamical properties of photoexcited carriers, particularly the charge transfer, in CdS–CdSe–CdS segmented nanorods using femtosecond transient pump–probe spectroscopy. Design of this kind of heteronanostructures with the possibility of variation of the relative volumes of CdS and C...

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Main Authors: Subha, Radhu, Nalla, Venkatram, Lim, Eugene J. Q., Vijayan, Cherianath, Huang, Barry. B. S., Chin, Wee Shong, Ji, Wei
Other Authors: School of Physical and Mathematical Sciences
Format: Article
Language:English
Published: 2015
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Online Access:https://hdl.handle.net/10356/103618
http://hdl.handle.net/10220/24595
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1036182023-02-28T19:44:39Z Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods Subha, Radhu Nalla, Venkatram Lim, Eugene J. Q. Vijayan, Cherianath Huang, Barry. B. S. Chin, Wee Shong Ji, Wei School of Physical and Mathematical Sciences DRNTU::Science::Physics::Optics and light DRNTU::Engineering::Nanotechnology DRNTU::Engineering::Materials::Photonics and optoelectronics materials We report on the dynamical properties of photoexcited carriers, particularly the charge transfer, in CdS–CdSe–CdS segmented nanorods using femtosecond transient pump–probe spectroscopy. Design of this kind of heteronanostructures with the possibility of variation of the relative volumes of CdS and CdSe segments permits independent tuning of one-photon and two-photon absorption cross-sections over a wide range of wavelengths, with specific advantages in applications related to photovoltaics and multiphoton microscopy. Intensity-dependent charge transfer dynamics in CdS–CdSe–CdS segmented nanorods indicates that the rate of charge transfer from CdS to CdSe is influenced by the number of electron–hole pairs generated in the nanorod. We attribute this change in the rate constant to Auger recombination-assisted charge transfer, which becomes the predominant relaxation mechanism at high intensities. Charge transfer also results in a large two-photon absorption cross-section, on the order of 104 GM (1 GM = 10–50 cm4 s photon–1), at 1.55 eV in these heteronanostructures. Furthermore, two-photon absorption induced photoluminescence on near-infrared excitation (1.55–0.99 eV) suggests that the local field effects plays a role in determining the effective two-photon action cross-section of heteronanostructures, offering a platform for engineering optical nonlinearity. Accepted version 2015-01-14T01:56:19Z 2019-12-06T21:16:24Z 2015-01-14T01:56:19Z 2019-12-06T21:16:24Z 2014 2014 Journal Article Subha, R., Nalla, V., Lim, E. J. Q., Vijayan, C., Huang, B. B. S., Chin, W. S., et al. (2014). Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods. ACS photonics, 2(1), 43-52. https://hdl.handle.net/10356/103618 http://hdl.handle.net/10220/24595 10.1021/ph500109h en ACS photonics © 2014 American Chemical Society.This is the author created version of a work that has been peer reviewed and accepted for publication by ACS Photonics, American Chemical Society. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1021/ph500109h]. 30 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Science::Physics::Optics and light
DRNTU::Engineering::Nanotechnology
DRNTU::Engineering::Materials::Photonics and optoelectronics materials
spellingShingle DRNTU::Science::Physics::Optics and light
DRNTU::Engineering::Nanotechnology
DRNTU::Engineering::Materials::Photonics and optoelectronics materials
Subha, Radhu
Nalla, Venkatram
Lim, Eugene J. Q.
Vijayan, Cherianath
Huang, Barry. B. S.
Chin, Wee Shong
Ji, Wei
Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods
description We report on the dynamical properties of photoexcited carriers, particularly the charge transfer, in CdS–CdSe–CdS segmented nanorods using femtosecond transient pump–probe spectroscopy. Design of this kind of heteronanostructures with the possibility of variation of the relative volumes of CdS and CdSe segments permits independent tuning of one-photon and two-photon absorption cross-sections over a wide range of wavelengths, with specific advantages in applications related to photovoltaics and multiphoton microscopy. Intensity-dependent charge transfer dynamics in CdS–CdSe–CdS segmented nanorods indicates that the rate of charge transfer from CdS to CdSe is influenced by the number of electron–hole pairs generated in the nanorod. We attribute this change in the rate constant to Auger recombination-assisted charge transfer, which becomes the predominant relaxation mechanism at high intensities. Charge transfer also results in a large two-photon absorption cross-section, on the order of 104 GM (1 GM = 10–50 cm4 s photon–1), at 1.55 eV in these heteronanostructures. Furthermore, two-photon absorption induced photoluminescence on near-infrared excitation (1.55–0.99 eV) suggests that the local field effects plays a role in determining the effective two-photon action cross-section of heteronanostructures, offering a platform for engineering optical nonlinearity.
author2 School of Physical and Mathematical Sciences
author_facet School of Physical and Mathematical Sciences
Subha, Radhu
Nalla, Venkatram
Lim, Eugene J. Q.
Vijayan, Cherianath
Huang, Barry. B. S.
Chin, Wee Shong
Ji, Wei
format Article
author Subha, Radhu
Nalla, Venkatram
Lim, Eugene J. Q.
Vijayan, Cherianath
Huang, Barry. B. S.
Chin, Wee Shong
Ji, Wei
author_sort Subha, Radhu
title Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods
title_short Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods
title_full Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods
title_fullStr Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods
title_full_unstemmed Slow down of charge transfer owing to auger recombination and two-photon action cross-section of CdS–CdSe–CdS segmented nanorods
title_sort slow down of charge transfer owing to auger recombination and two-photon action cross-section of cds–cdse–cds segmented nanorods
publishDate 2015
url https://hdl.handle.net/10356/103618
http://hdl.handle.net/10220/24595
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