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...

Full description

Bibliographic Details
Main Author: Yew, Pauline
Format: Thesis
Language:English
Published: 2018
Subjects:
Online Access:http://eprints.usm.my/47818/
http://eprints.usm.my/47818/1/PAULINE%20YEW%20-%20INFRARED%20DIELECTRIC%20CHARACTERISTICS.pdf
_version_ 1848880983469719552
author Yew, Pauline
author_facet Yew, Pauline
author_sort Yew, Pauline
building USM Institutional Repository
collection Online Access
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.
first_indexed 2025-11-15T18:11:47Z
format Thesis
id usm-47818
institution Universiti Sains Malaysia
institution_category Local University
language English
last_indexed 2025-11-15T18:11:47Z
publishDate 2018
recordtype eprints
repository_type Digital Repository
spelling usm-478182020-10-28T06:43:33Z http://eprints.usm.my/47818/ Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures 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 NonPeerReviewed application/pdf en http://eprints.usm.my/47818/1/PAULINE%20YEW%20-%20INFRARED%20DIELECTRIC%20CHARACTERISTICS.pdf Yew, Pauline (2018) Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures. PhD thesis, Universiti Sains Malaysia.
spellingShingle QC1 Physics (General)
Yew, Pauline
Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
title 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_short Infrared Dielectric Characteristics Of Porous Binary And Ternary Iii-Nitrides Heterostructures
title_sort infrared dielectric characteristics of porous binary and ternary iii-nitrides heterostructures
topic QC1 Physics (General)
url http://eprints.usm.my/47818/
http://eprints.usm.my/47818/1/PAULINE%20YEW%20-%20INFRARED%20DIELECTRIC%20CHARACTERISTICS.pdf