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Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman

Conventional gallium nitride (GaN)-based light-emitting diodes (LEDs), commonly grown in the c-plane direction suffer from the huge built-in electric field from spontaneous and piezoelectric polarisation, which cause the energy-band bending in the energy band diagram. Motivated to avoid the undesira...

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Main Author: Anas , Kamarundzaman
Format: Thesis
Published: 2022
Subjects:
Q Science (General)
QC Physics
Online Access:http://studentsrepo.um.edu.my/15197/2/Anas_Kamarundzaman.pdf
http://studentsrepo.um.edu.my/15197/1/Anas_Kamarundzaman.pdf
http://studentsrepo.um.edu.my/15197/
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spelling my.um.stud.151972024-11-25T23:13:08Z Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman Anas , Kamarundzaman Q Science (General) QC Physics Conventional gallium nitride (GaN)-based light-emitting diodes (LEDs), commonly grown in the c-plane direction suffer from the huge built-in electric field from spontaneous and piezoelectric polarisation, which cause the energy-band bending in the energy band diagram. Motivated to avoid the undesirable polarisation effect, this study explored the growth of the non-polar (11–20) a-plane GaN. In this study, the full structure of the a-plane InGaN/GaN LED epitaxial was grown on a two-inch r-plane sapphire substrate using Taiyo Nippon Sanso SR-2000 metal-organic chemical vapour deposition (MOCVD). The LED’s structure consisted of four main layers, which were undoped gallium nitride (ud-GaN), n-type GaN, p-type GaN and the active region of InGaN/GaN multi-quantum well (MQW). Several optimisations were employed in the epitaxial growth of ud-GaN, which were the GaN nucleation layer, the V/III ratio and the insertion of the periodic AlN/GaN multilayers (MLs) at different positions, as well as the number of AlN/GaN ML pairs. The a-plane ud-GaN with a low-temperature nucleation layer (NL), a low V/III ratio and 120 pairs of AlN/GaNMLs showed the best crystalline quality with the full width at half maximum (FWHM) value of 756 arcsec and surface roughness of 2.15 nm from the X-ray rocking curve (XRC) scan. The n- and p-type GaN were tuned by varying the flow rates of disilane and Cp2Mg, respectively. Both n- and p-type GaN showed the best electrical properties at the highest doping flow rate, with carrier concentration and mobility of 4.94 × 1019 cm-³ and 58.39 cm2/V•s for the n-GaN, respectively, and 2.13 × 1018 cm-³ and 20.46 cm2/V•s for the p-GaN, respectively. The full a-plane InGaN/GaN LED was grown on top of different ud-GaN structures, while utilising the suitable n- and p-type GaN. Significant improvements in light output power from 10 μW at 100 mA to 70 μW were recorded when the growth of the InGaN/GaN LED utilised 120 pairs of AlN/GaN MLs. 2022-01 Thesis NonPeerReviewed application/pdf http://studentsrepo.um.edu.my/15197/2/Anas_Kamarundzaman.pdf application/pdf http://studentsrepo.um.edu.my/15197/1/Anas_Kamarundzaman.pdf Anas , Kamarundzaman (2022) Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman. PhD thesis, Universiti Malaya. http://studentsrepo.um.edu.my/15197/
institution Universiti Malaya
building UM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaya
content_source UM Student Repository
url_provider http://studentsrepo.um.edu.my/
topic Q Science (General)
QC Physics
spellingShingle Q Science (General)
QC Physics
Anas , Kamarundzaman
Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman
description Conventional gallium nitride (GaN)-based light-emitting diodes (LEDs), commonly grown in the c-plane direction suffer from the huge built-in electric field from spontaneous and piezoelectric polarisation, which cause the energy-band bending in the energy band diagram. Motivated to avoid the undesirable polarisation effect, this study explored the growth of the non-polar (11–20) a-plane GaN. In this study, the full structure of the a-plane InGaN/GaN LED epitaxial was grown on a two-inch r-plane sapphire substrate using Taiyo Nippon Sanso SR-2000 metal-organic chemical vapour deposition (MOCVD). The LED’s structure consisted of four main layers, which were undoped gallium nitride (ud-GaN), n-type GaN, p-type GaN and the active region of InGaN/GaN multi-quantum well (MQW). Several optimisations were employed in the epitaxial growth of ud-GaN, which were the GaN nucleation layer, the V/III ratio and the insertion of the periodic AlN/GaN multilayers (MLs) at different positions, as well as the number of AlN/GaN ML pairs. The a-plane ud-GaN with a low-temperature nucleation layer (NL), a low V/III ratio and 120 pairs of AlN/GaNMLs showed the best crystalline quality with the full width at half maximum (FWHM) value of 756 arcsec and surface roughness of 2.15 nm from the X-ray rocking curve (XRC) scan. The n- and p-type GaN were tuned by varying the flow rates of disilane and Cp2Mg, respectively. Both n- and p-type GaN showed the best electrical properties at the highest doping flow rate, with carrier concentration and mobility of 4.94 × 1019 cm-³ and 58.39 cm2/V•s for the n-GaN, respectively, and 2.13 × 1018 cm-³ and 20.46 cm2/V•s for the p-GaN, respectively. The full a-plane InGaN/GaN LED was grown on top of different ud-GaN structures, while utilising the suitable n- and p-type GaN. Significant improvements in light output power from 10 μW at 100 mA to 70 μW were recorded when the growth of the InGaN/GaN LED utilised 120 pairs of AlN/GaN MLs.
format Thesis
author Anas , Kamarundzaman
author_facet Anas , Kamarundzaman
author_sort Anas , Kamarundzaman
title Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman
title_short Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman
title_full Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman
title_fullStr Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman
title_full_unstemmed Growth of non-polar (11-20) a-plane GaN based leds grown on (1-120) r-plane sapphire substrate via MOCVD / Anas Kamarundzaman
title_sort growth of non-polar (11-20) a-plane gan based leds grown on (1-120) r-plane sapphire substrate via mocvd / anas kamarundzaman
publishDate 2022
url http://studentsrepo.um.edu.my/15197/2/Anas_Kamarundzaman.pdf
http://studentsrepo.um.edu.my/15197/1/Anas_Kamarundzaman.pdf
http://studentsrepo.um.edu.my/15197/
_version_ 1817842516074954752
score 13.223943

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