Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures

Porosity and composition dependence of infrared (IR) dielectric function of wurtzite III-nitrides are explored theoretically and experimentally. “Suspension-like” (i.e., porous GaN) and “solution-like” (i.e., InxGa1-xN) mixture are employed to investigate porosity and composition dependence of IR di...

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Main Author: Yew, Pauline
Format: Thesis
Language:English
Published: 2018
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Online Access:http://eprints.usm.my/47818/1/PAULINE%20YEW%20-%20INFRARED%20DIELECTRIC%20CHARACTERISTICS.pdf
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spelling my-usm-ep.478182020-10-28T06:43:33Z Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures 2018-08 Yew, Pauline QC1 Physics (General) Porosity and composition dependence of infrared (IR) dielectric function of wurtzite III-nitrides are explored theoretically and experimentally. “Suspension-like” (i.e., porous GaN) and “solution-like” (i.e., InxGa1-xN) mixture are employed to investigate porosity and composition dependence of IR dielectric function respectively. Although many effective medium theories (EMTs) are available in literature, selection of appropriate EMT to describe the effective dielectric response for “suspension-like” mixture remains challenging and ambiguous. Therefore, an in-depth study on the effective dielectric properties for two-component mixtures which have four possible combinations of dielectric functions is performed. A comprehensive guideline for selecting the EMT to describe the effective dielectric behaviour of “suspension-like” mixture is proposed. Subsequently, polarized IR reflectance measurements of a set of porous GaN samples (PGaN) are performed to investigate the best EMT in describing the PGaN system as well as the impact of porosity on effective dielectric function. The reflectance spectra of PGaN can be fully described by factorized-Rayleigh (Ra) model which is developed for the first time to account for the damping of Fröhlich modes. Two weak Fröhlich modes are detected in the s-polarized IR reflectance spectra of PGaN at 710 cm-1 and 730 cm-1. This implies that two additional surface phonon polariton (SPhP) modes are expected to appear in p-polarized IR attenuated total reflection spectra of PGaN. Besides, a red shift of SPhP mode of PGaN with increasing porosity can be predicted using factorized-Ra model. 2018-08 Thesis http://eprints.usm.my/47818/ http://eprints.usm.my/47818/1/PAULINE%20YEW%20-%20INFRARED%20DIELECTRIC%20CHARACTERISTICS.pdf application/pdf en public phd doctoral Universiti Sains Malaysia Pusat Pengajian Sains Fizik
institution Universiti Sains Malaysia
collection USM Institutional Repository
language English
topic QC1 Physics (General)
spellingShingle QC1 Physics (General)
Yew, Pauline
Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
description Porosity and composition dependence of infrared (IR) dielectric function of wurtzite III-nitrides are explored theoretically and experimentally. “Suspension-like” (i.e., porous GaN) and “solution-like” (i.e., InxGa1-xN) mixture are employed to investigate porosity and composition dependence of IR dielectric function respectively. Although many effective medium theories (EMTs) are available in literature, selection of appropriate EMT to describe the effective dielectric response for “suspension-like” mixture remains challenging and ambiguous. Therefore, an in-depth study on the effective dielectric properties for two-component mixtures which have four possible combinations of dielectric functions is performed. A comprehensive guideline for selecting the EMT to describe the effective dielectric behaviour of “suspension-like” mixture is proposed. Subsequently, polarized IR reflectance measurements of a set of porous GaN samples (PGaN) are performed to investigate the best EMT in describing the PGaN system as well as the impact of porosity on effective dielectric function. The reflectance spectra of PGaN can be fully described by factorized-Rayleigh (Ra) model which is developed for the first time to account for the damping of Fröhlich modes. Two weak Fröhlich modes are detected in the s-polarized IR reflectance spectra of PGaN at 710 cm-1 and 730 cm-1. This implies that two additional surface phonon polariton (SPhP) modes are expected to appear in p-polarized IR attenuated total reflection spectra of PGaN. Besides, a red shift of SPhP mode of PGaN with increasing porosity can be predicted using factorized-Ra model.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Yew, Pauline
author_facet Yew, Pauline
author_sort Yew, Pauline
title Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
title_short Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
title_full Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
title_fullStr Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
title_full_unstemmed Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
title_sort infrared dielectric characteristics of porous binary and ternary iii-nitrides heterostructures
granting_institution Universiti Sains Malaysia
granting_department Pusat Pengajian Sains Fizik
publishDate 2018
url http://eprints.usm.my/47818/1/PAULINE%20YEW%20-%20INFRARED%20DIELECTRIC%20CHARACTERISTICS.pdf
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