Optical characterization of metal oxide thin films

Optical properties including complex dielectric function and band gap of ZnO, indium gallium zinc oxide (IGZO) and Al-doped ZnO (AZO) thin films were studied with spectroscopic ellipsometry based on various optical dispersion models. ZnO thin film exhibits a slightly blue shift in both real and imag...

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Main Author: Ng, Marcus Jian Wei
Other Authors: Chen Tupei
Format: Final Year Project (FYP)
Language:English
Published: 2015
Subjects:
Online Access:http://hdl.handle.net/10356/63844
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author Ng, Marcus Jian Wei
author2 Chen Tupei
author_facet Chen Tupei
Ng, Marcus Jian Wei
author_sort Ng, Marcus Jian Wei
collection NTU
description Optical properties including complex dielectric function and band gap of ZnO, indium gallium zinc oxide (IGZO) and Al-doped ZnO (AZO) thin films were studied with spectroscopic ellipsometry based on various optical dispersion models. ZnO thin film exhibits a slightly blue shift in both real and imaginary parts of complex dielectric function. The expansion of band gap of ZnO thin films could be attributed to the Burstein-Moss effect due to the increase of electron concentration in the thicker films. On the other hand, IGZO thin film shows a significant blue shift of band gap energy with increasing film thickness. The evolution of the band gap energy and the dielectric function are related to the changes of electron concentration in the films. Dielectric function of AZO thin film showed a blue shift under annealing temperatures < 500°C and a red shift > 500°C. The blue shift can be explained as the Burstein–Moss effect where the band gap increases with the increases of free electron concentrations in the films. It could be attributed to the changes of donor-like defect concentration such as oxygen vacancies in the films caused by annealing.
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spelling ntu-10356/638442023-07-07T17:24:49Z Optical characterization of metal oxide thin films Ng, Marcus Jian Wei Chen Tupei School of Electrical and Electronic Engineering DRNTU::Engineering::Electrical and electronic engineering::Semiconductors DRNTU::Engineering::Electrical and electronic engineering::Microelectronics Optical properties including complex dielectric function and band gap of ZnO, indium gallium zinc oxide (IGZO) and Al-doped ZnO (AZO) thin films were studied with spectroscopic ellipsometry based on various optical dispersion models. ZnO thin film exhibits a slightly blue shift in both real and imaginary parts of complex dielectric function. The expansion of band gap of ZnO thin films could be attributed to the Burstein-Moss effect due to the increase of electron concentration in the thicker films. On the other hand, IGZO thin film shows a significant blue shift of band gap energy with increasing film thickness. The evolution of the band gap energy and the dielectric function are related to the changes of electron concentration in the films. Dielectric function of AZO thin film showed a blue shift under annealing temperatures < 500°C and a red shift > 500°C. The blue shift can be explained as the Burstein–Moss effect where the band gap increases with the increases of free electron concentrations in the films. It could be attributed to the changes of donor-like defect concentration such as oxygen vacancies in the films caused by annealing. Bachelor of Engineering 2015-05-19T06:43:19Z 2015-05-19T06:43:19Z 2015 2015 Final Year Project (FYP) http://hdl.handle.net/10356/63844 en Nanyang Technological University 48 p. application/pdf
spellingShingle DRNTU::Engineering::Electrical and electronic engineering::Semiconductors
DRNTU::Engineering::Electrical and electronic engineering::Microelectronics
Ng, Marcus Jian Wei
Optical characterization of metal oxide thin films
title Optical characterization of metal oxide thin films
title_full Optical characterization of metal oxide thin films
title_fullStr Optical characterization of metal oxide thin films
title_full_unstemmed Optical characterization of metal oxide thin films
title_short Optical characterization of metal oxide thin films
title_sort optical characterization of metal oxide thin films
topic DRNTU::Engineering::Electrical and electronic engineering::Semiconductors
DRNTU::Engineering::Electrical and electronic engineering::Microelectronics
url http://hdl.handle.net/10356/63844
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