First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties

An efficient diagnostic between experimental and theoretical calculation is essential to ensure the synergy between these two approaches. This study made attempt to use structural input from experimental in the theoretical framework. Initially, ZnO nanoparticles were synthesized by sol-gel method...

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Main Author:	Harun, Kausar
Format:	Thesis
Language:	English
Published:	2018
Subjects:	T Technology
Online Access:	http://eprints.usm.my/47338/1/First-Principles%20Calculations%20On%20Solgel%20Zinc%20Oxide%20Nanoparticles%20Optoelectronic%20Properties.pdf
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spelling	my-usm-ep.473382021-11-17T03:42:14Z First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties 2018-02-01 Harun, Kausar T Technology TA401-492 Materials of engineering and construction. Mechanics of materials An efficient diagnostic between experimental and theoretical calculation is essential to ensure the synergy between these two approaches. This study made attempt to use structural input from experimental in the theoretical framework. Initially, ZnO nanoparticles were synthesized by sol-gel method at different aging time. The phase and structural analyses confirmed the formation of hexagonal wurtzite ZnO structure at which sample aged at 36 h showed highest crystallinity and gave the best visual fit in Rietveld analysis. Morphological observation revealed spherical nanoparticles were formed at aging time higher than 6 h while only small variation in energy band gap recorded between 3.08 – 3.12 eV. The photoluminescence spectra revealed a green emission due to oxygen vacany. In firstprinciples calculation, the ZnO unit cell was built based on structural parameter from Rietveld analysis in order to provide a bridge with experimental study. Several exchange-correlation functional including LDA, GGA-PBE, GGA-PBESol, LDA+U, GGA-PBE+U and GGA-PBESol+U were tested. The GGA-PBE+U (Ud,Zn = 10 eV and Up,O = 6.1 eV) showed lowest lattice deviation and successfully reproduced the experimental band gap. ZnO supercell structure with oxygen vacancy showed that defect state were more delocalized and appeared at 1.90 eV from top of conduction band. This position was close to the photon energy released due to recombination of electron (2.06 eV) as observed in luminescence spectra. The results are beneficial in designing photoanode material in solar cell that will enhance visible light absorption. 2018-02 Thesis http://eprints.usm.my/47338/ http://eprints.usm.my/47338/1/First-Principles%20Calculations%20On%20Solgel%20Zinc%20Oxide%20Nanoparticles%20Optoelectronic%20Properties.pdf application/pdf en public masters Universiti Sains Malaysia Pusat Pengajian Kejuruteraan Bahan & Sumber Mineral
institution	Universiti Sains Malaysia
collection	USM Institutional Repository
language	English
topic	T Technology T Technology
spellingShingle	T Technology T Technology Harun, Kausar First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties
description	An efficient diagnostic between experimental and theoretical calculation is essential to ensure the synergy between these two approaches. This study made attempt to use structural input from experimental in the theoretical framework. Initially, ZnO nanoparticles were synthesized by sol-gel method at different aging time. The phase and structural analyses confirmed the formation of hexagonal wurtzite ZnO structure at which sample aged at 36 h showed highest crystallinity and gave the best visual fit in Rietveld analysis. Morphological observation revealed spherical nanoparticles were formed at aging time higher than 6 h while only small variation in energy band gap recorded between 3.08 – 3.12 eV. The photoluminescence spectra revealed a green emission due to oxygen vacany. In firstprinciples calculation, the ZnO unit cell was built based on structural parameter from Rietveld analysis in order to provide a bridge with experimental study. Several exchange-correlation functional including LDA, GGA-PBE, GGA-PBESol, LDA+U, GGA-PBE+U and GGA-PBESol+U were tested. The GGA-PBE+U (Ud,Zn = 10 eV and Up,O = 6.1 eV) showed lowest lattice deviation and successfully reproduced the experimental band gap. ZnO supercell structure with oxygen vacancy showed that defect state were more delocalized and appeared at 1.90 eV from top of conduction band. This position was close to the photon energy released due to recombination of electron (2.06 eV) as observed in luminescence spectra. The results are beneficial in designing photoanode material in solar cell that will enhance visible light absorption.
format	Thesis
qualification_level	Master's degree
author	Harun, Kausar
author_facet	Harun, Kausar
author_sort	Harun, Kausar
title	First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties
title_short	First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties
title_full	First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties
title_fullStr	First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties
title_full_unstemmed	First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties
title_sort	first-principles calculations on solgel zinc oxide nanoparticles optoelectronic properties
granting_institution	Universiti Sains Malaysia
granting_department	Pusat Pengajian Kejuruteraan Bahan & Sumber Mineral
publishDate	2018
url	http://eprints.usm.my/47338/1/First-Principles%20Calculations%20On%20Solgel%20Zinc%20Oxide%20Nanoparticles%20Optoelectronic%20Properties.pdf
_version_	1747821761346404352

First-Principles Calculations On Solgel Zinc Oxide Nanoparticles Optoelectronic Properties

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