Effect of thermal annealing on the luminescence of defective ZnO nanoparticles synthesized by pulsed laser ablation in water

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Abstract

This work concerns ZnO nanoparticles (NPs), with sizes of tens of nm, produced by ablation with a pulsed Nd:YAG laser of a Zn plate in H2O. TEM images evidence the formation of nanoparticles with sizes of tens of nm. Moreover, HRTEM images and Raman spectra show that the distance between the crystalline planes and the vibrational modes are consistent with ZnO nanocrystal in wurtzite structure. Their optical properties are characterized by two emission bands both excited above the energy gap (3.4 eV): the first at 3.3 eV is associated with excitons recombination, the second at 2.2 eV is proposed to originate from a singly ionized oxygen vacancy. The green emission is independent of water pH, thus suggesting that point defects lie inside NPs rather than at the surface. Thermal annealing at 300 �C in O2and He atmosphere, produces a reduction of the A1(LO) Raman mode at 562 cm-1, which is related to the oxygen vacancies, and a consequent decrease of the defect luminescence, while the excitonic luminescence increases. These results indicate that the ZnO emissions can be controlled by thermal annealing, and are promising in view of optoelectronic applications. (� 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).
Lingua originaleEnglish
pagine (da-a)890-894
Numero di pagine5
RivistaPHYSICA STATUS SOLIDI. C, CURRENT TOPICS IN SOLID STATE PHYSICS
Volume13
Stato di pubblicazionePublished - 2016

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laser ablation
pulsed lasers
luminescence
nanoparticles
annealing
water
oxygen
wurtzite
point defects
ablation
YAG lasers
vibration mode
nanocrystals
excitons
Raman spectra
optical properties
atmospheres
transmission electron microscopy
defects

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cita questo

@article{ee7f190f65954d4182ab05595774aca5,
title = "Effect of thermal annealing on the luminescence of defective ZnO nanoparticles synthesized by pulsed laser ablation in water",
abstract = "This work concerns ZnO nanoparticles (NPs), with sizes of tens of nm, produced by ablation with a pulsed Nd:YAG laser of a Zn plate in H2O. TEM images evidence the formation of nanoparticles with sizes of tens of nm. Moreover, HRTEM images and Raman spectra show that the distance between the crystalline planes and the vibrational modes are consistent with ZnO nanocrystal in wurtzite structure. Their optical properties are characterized by two emission bands both excited above the energy gap (3.4 eV): the first at 3.3 eV is associated with excitons recombination, the second at 2.2 eV is proposed to originate from a singly ionized oxygen vacancy. The green emission is independent of water pH, thus suggesting that point defects lie inside NPs rather than at the surface. Thermal annealing at 300 {\"i}¿½C in O2and He atmosphere, produces a reduction of the A1(LO) Raman mode at 562 cm-1, which is related to the oxygen vacancies, and a consequent decrease of the defect luminescence, while the excitonic luminescence increases. These results indicate that the ZnO emissions can be controlled by thermal annealing, and are promising in view of optoelectronic applications. ({\"i}¿½ 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).",
author = "Gelardi, {Franco Mario} and Gianpiero Buscarino and Fabrizio Messina and Simonpietro Agnello and Lavinia Vaccaro and Marco Cannas and Pietro Camarda and Radian Popescu and Schneider",
year = "2016",
language = "English",
volume = "13",
pages = "890--894",
journal = "Physica Status Solidi (C) Current Topics in Solid State Physics",
issn = "1862-6351",
publisher = "Wiley-VCH Verlag",

}

TY - JOUR

T1 - Effect of thermal annealing on the luminescence of defective ZnO nanoparticles synthesized by pulsed laser ablation in water

AU - Gelardi, Franco Mario

AU - Buscarino, Gianpiero

AU - Messina, Fabrizio

AU - Agnello, Simonpietro

AU - Vaccaro, Lavinia

AU - Cannas, Marco

AU - Camarda, Pietro

AU - Popescu, Radian

AU - Schneider, null

PY - 2016

Y1 - 2016

N2 - This work concerns ZnO nanoparticles (NPs), with sizes of tens of nm, produced by ablation with a pulsed Nd:YAG laser of a Zn plate in H2O. TEM images evidence the formation of nanoparticles with sizes of tens of nm. Moreover, HRTEM images and Raman spectra show that the distance between the crystalline planes and the vibrational modes are consistent with ZnO nanocrystal in wurtzite structure. Their optical properties are characterized by two emission bands both excited above the energy gap (3.4 eV): the first at 3.3 eV is associated with excitons recombination, the second at 2.2 eV is proposed to originate from a singly ionized oxygen vacancy. The green emission is independent of water pH, thus suggesting that point defects lie inside NPs rather than at the surface. Thermal annealing at 300 �C in O2and He atmosphere, produces a reduction of the A1(LO) Raman mode at 562 cm-1, which is related to the oxygen vacancies, and a consequent decrease of the defect luminescence, while the excitonic luminescence increases. These results indicate that the ZnO emissions can be controlled by thermal annealing, and are promising in view of optoelectronic applications. (� 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

AB - This work concerns ZnO nanoparticles (NPs), with sizes of tens of nm, produced by ablation with a pulsed Nd:YAG laser of a Zn plate in H2O. TEM images evidence the formation of nanoparticles with sizes of tens of nm. Moreover, HRTEM images and Raman spectra show that the distance between the crystalline planes and the vibrational modes are consistent with ZnO nanocrystal in wurtzite structure. Their optical properties are characterized by two emission bands both excited above the energy gap (3.4 eV): the first at 3.3 eV is associated with excitons recombination, the second at 2.2 eV is proposed to originate from a singly ionized oxygen vacancy. The green emission is independent of water pH, thus suggesting that point defects lie inside NPs rather than at the surface. Thermal annealing at 300 �C in O2and He atmosphere, produces a reduction of the A1(LO) Raman mode at 562 cm-1, which is related to the oxygen vacancies, and a consequent decrease of the defect luminescence, while the excitonic luminescence increases. These results indicate that the ZnO emissions can be controlled by thermal annealing, and are promising in view of optoelectronic applications. (� 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

UR - http://hdl.handle.net/10447/288462

M3 - Article

VL - 13

SP - 890

EP - 894

JO - Physica Status Solidi (C) Current Topics in Solid State Physics

JF - Physica Status Solidi (C) Current Topics in Solid State Physics

SN - 1862-6351

ER -