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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2022
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| 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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| author | Anas , Kamarundzaman |
| author_facet | Anas , Kamarundzaman |
| author_sort | Anas , Kamarundzaman |
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| 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.
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| format | Thesis |
| id | my.um.stud-15197 |
| institution | Universiti Malaya |
| publishDate | 2022 |
| record_format | eprints |
| 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/ |
| 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 |
| 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_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_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_sort | growth of non-polar (11-20) a-plane gan based leds grown on (1-120) r-plane sapphire substrate via mocvd / anas kamarundzaman |
| topic | Q Science (General) QC Physics |
| 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/ |
| url_provider | http://studentsrepo.um.edu.my/ |