Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals
Type
ArticleAuthors
Tsai, Yu-LinLiu, 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

KAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionElectrical Engineering Program
KAUST Solar Center (KSC)
Date
2016Permanent link to this record
http://hdl.handle.net/10754/583403
Metadata
Show full item recordAbstract
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.Citation
Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals 2015 NanoscalePublisher
Royal Society of Chemistry (RSC)Journal
NanoscalePubMed ID
26666367Additional Links
http://pubs.rsc.org/en/Content/ArticleLanding/2015/NR/C5NR05555Eae974a485f413a2113503eed53cd6c53
10.1039/C5NR05555E
Scopus Count
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