Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals

Handle URI:
http://hdl.handle.net/10754/583403
Title:
Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals
Authors:
Tsai, Yu-Lin; Liu, Che-Yu; Krishnan, Chirenjeevi; Lin, Da-Wei; Chu, You-Chen; Chen, Tzu-Pei; Shen, Tien-Lin; Kao, Tsung-Sheng; Charlton, Martin; Yu, Peichen; Lin, Chien-Chung; Kuo, Hao-Chung; He, Jr-Hau ( 0000-0003-1886-9241 )
Abstract:
Green LEDs do not show the same level of performance as their blue and red cousins, greatly hindering the solid-state lighting development, which is so-called “green gap”. In this work, nano-void photonic crystals (NVPCs) were fabricated to embed within the GaN/InGaN green LEDs by using epitaxial lateral overgrowth (ELO) and nano-sphere lithography techniques. The NVPCs act as an efficient scattering back-reflector to outcouple the guided and downward photons, which not only boosting light extraction efficiency of LEDs with an enhancement of 78% but also collimating the view angle of LEDs from 131.5゜to 114.0゜. This could be because the highly scattering nature of NVPCs which reduce the interference giving rise to Fabry-Perot resonance. Moreover, due to the threading dislocation suppression and strain relief by the NVPCs, the internal quantum efficiency was increased by 25% and droop behavior was reduced from 37.4% to 25.9%. The enhancement of light output power can be achieved as high as 151% at a driving current of 350 mA. Giant light output enhancement and directional control via NVPCs points the way towards a promising avenue of solid-state lighting.
KAUST Department:
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Citation:
Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals 2015 Nanoscale
Publisher:
Royal Society of Chemistry (RSC)
Journal:
Nanoscale
Issue Date:
23-Nov-2015
DOI:
10.1039/C5NR05555E
Type:
Article
ISSN:
2040-3364; 2040-3372
Additional Links:
http://pubs.rsc.org/en/Content/ArticleLanding/2015/NR/C5NR05555E
Appears in Collections:
Articles; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorTsai, Yu-Linen
dc.contributor.authorLiu, Che-Yuen
dc.contributor.authorKrishnan, Chirenjeevien
dc.contributor.authorLin, Da-Weien
dc.contributor.authorChu, You-Chenen
dc.contributor.authorChen, Tzu-Peien
dc.contributor.authorShen, Tien-Linen
dc.contributor.authorKao, Tsung-Shengen
dc.contributor.authorCharlton, Martinen
dc.contributor.authorYu, Peichenen
dc.contributor.authorLin, Chien-Chungen
dc.contributor.authorKuo, Hao-Chungen
dc.contributor.authorHe, Jr-Hauen
dc.date.accessioned2015-12-08T13:35:34Zen
dc.date.available2015-12-08T13:35:34Zen
dc.date.issued2015-11-23en
dc.identifier.citationBridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals 2015 Nanoscaleen
dc.identifier.issn2040-3364en
dc.identifier.issn2040-3372en
dc.identifier.doi10.1039/C5NR05555Een
dc.identifier.urihttp://hdl.handle.net/10754/583403en
dc.description.abstractGreen LEDs do not show the same level of performance as their blue and red cousins, greatly hindering the solid-state lighting development, which is so-called “green gap”. In this work, nano-void photonic crystals (NVPCs) were fabricated to embed within the GaN/InGaN green LEDs by using epitaxial lateral overgrowth (ELO) and nano-sphere lithography techniques. The NVPCs act as an efficient scattering back-reflector to outcouple the guided and downward photons, which not only boosting light extraction efficiency of LEDs with an enhancement of 78% but also collimating the view angle of LEDs from 131.5゜to 114.0゜. This could be because the highly scattering nature of NVPCs which reduce the interference giving rise to Fabry-Perot resonance. Moreover, due to the threading dislocation suppression and strain relief by the NVPCs, the internal quantum efficiency was increased by 25% and droop behavior was reduced from 37.4% to 25.9%. The enhancement of light output power can be achieved as high as 151% at a driving current of 350 mA. Giant light output enhancement and directional control via NVPCs points the way towards a promising avenue of solid-state lighting.en
dc.language.isoenen
dc.publisherRoyal Society of Chemistry (RSC)en
dc.relation.urlhttp://pubs.rsc.org/en/Content/ArticleLanding/2015/NR/C5NR05555Een
dc.rightsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Nanoscale, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.rsc.org/en/Content/ArticleLanding/2015/NR/C5NR05555E.en
dc.titleBridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystalsen
dc.typeArticleen
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
dc.identifier.journalNanoscaleen
dc.eprint.versionPost-printen
dc.contributor.institutionDepartment of Photonics & Institute of Electro - Optical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan, ROCen
dc.contributor.institutionSchool of Electronics and Computer Science , University of Southampton, Southampton SO17 1BJ, United Kingdomen
dc.contributor.institutionInstitute of Photonic System, National Chiao Tung University, Tainan 711, Taiwan, ROCen
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorTsai, Yu-Linen
kaust.authorHe, Jr-Hauen
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