Journal ArticleDOI
High-Performance GaN-Based Vertical-Injection Light-Emitting Diodes With TiO $_{2}$ –SiO $_{2}$ Omnidirectional Reflector and n-GaN Roughness
Huang-Hsiung Huang,H. C. Kuo,Chung-Yu Lai,C. E. Lee,C.W. Chiu,Tien-Chang Lu,S. C. Wang,Chuan-Hsien Lin,K. M. Leung +8 more
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TLDR
In this article, a new type of GaN-based thin-film vertical-injection light-emitting diode (LED) with TiO2-SiO 2 omnidirectional reflector (ODR) and n-GaN roughness was designed and fabricated.Abstract:
We have designed and fabricated a new type of GaN-based thin-film vertical-injection light-emitting diode (LED) with TiO2-SiO 2 omnidirectional reflector (ODR) and n-GaN roughness. The associated ODR designed for LED operation wavelength at 455 nm was integrated with patterned conducting channels for the purpose of vertical current spreading. With the help of laser lift-off and photo-electrochemical etching technologies, at a driving current of 350 mA and with chip size of 1 mm times 1 mm, the light-output power and the external quantum efficiency of our thin-film LED with TiO2-SiO2 ODR reached 330 mW and 26.7%. The result demonstrated 18% power enhancement when compared with the results from the thin-film LED with Al reflector replaceread more
Citations
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Patent
Semiconductor light emitting diodes having reflective structures and methods of fabricating same
TL;DR: In this paper, a diode region having first and second opposing faces is described, where an n-type and a p-type layer, an anode contact that ohmically contacts the p type layer and extends on the first face, and a cathode contact, which is configured to reflect substantially all light that emerges from a first face back into the second face.
Journal ArticleDOI
Increasing the reliability of solid state lighting systems via self-healing approaches: A review
TL;DR: Self-healing concepts will be proposed to further improve LED’s reliability in order to increase reliability of SSL devices, components presenting self-repairing properties could be implemented.
Patent
Reflector system for lighting device
Paul Kenneth Pickard,Ryan Kelley +1 more
Abstract: A reflector system for a lighting device. The system uses two reflective surfaces to redirect the light before it is emitted. The light source/sources are disposed at the base of a secondary reflector. The first reflective surface is provided by a primary reflector which is arranged proximate to the source/sources. The primary reflector initially redirects, and in some cases diffuses, light from the sources such that the different wavelengths of light are mixed as they are redirected toward the secondary reflector. The secondary reflector functions primarily to shape the light into a desired output beam. The primary and secondary reflectors may be specular or diffuse and may comprise faceted surfaces. The reflector arrangement allows the source to be placed at the base of the secondary reflector where it may be thermally coupled to a housing or another structure to provide an outlet for heat generated by the sources.
Patent
Composite high reflectivity layer
TL;DR: In this paper, a high efficiency light emitting diode (LED) with a composite high reflectivity layer integral to the LED to improve emission efficiency is presented. But it does not consider the effect of conductive vias on the composite layer.
Patent
High reflective substrate of light emitting devices with improved light output
TL;DR: In this article, the authors present an approach for producing light emitting devices with a substrate and a reflective layer at least partially covering the substrate, and a light diffusion lens may also be disposed on the substrate and surrounding the LEDs.
References
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Book
Photonic Crystals: Molding the Flow of Light
TL;DR: In this paper, the authors developed the theoretical tools of photonics using principles of linear algebra and symmetry, emphasizing analogies with traditional solid-state physics and quantum theory, and investigated the unique phenomena that take place within photonic crystals at defect sites and surfaces, from one to three dimensions.
Journal ArticleDOI
Solid-State Light Sources Getting Smart
E. Fred Schubert,Jong Kyu Kim +1 more
TL;DR: The high efficiency of solid-state sources already provides energy savings and environmental benefits in a number of applications, but these sources also offer controllability of their spectral power distribution, spatial distribution, color temperature, temporal modulation, and polarization properties.
Journal ArticleDOI
Increase in the extraction efficiency of GaN-based light-emitting diodes via surface roughening
TL;DR: In this paper, an n-side-up GaN-based LED with a hexagonal "conelike" surface has been fabricated by using the laser lift-off technique followed by an anisotropic etching process to roughen the surface.
Journal ArticleDOI
A Dielectric Omnidirectional Reflector
Yoel Fink,Joshua N. Winn,Shanhui Fan,Chiping Chen,Jurgen Michel,John D. Joannopoulos,Edwin L. Thomas +6 more
TL;DR: A design criterion that permits truly omnidirectional reflectivity for all polarizations of incident light over a wide selectable range of frequencies was used in fabricating an all-dielectric omnid Directional reflector consisting of multilayer films.
Journal ArticleDOI
Study of GaN light-emitting diodes fabricated by laser lift-off technique
Chen Fu Chu,Fang-I Lai,Jung Tang Chu,Yu Chang-Chin,Chia-Feng Lin,Hao-Chung Kuo,Shing-Chung Wang +6 more
TL;DR: In this article, the fabrication process and performance characteristics of the laser lift-off (LLO) GaN light-emitting diodes (LEDs) were investigated by lifting off the GaN LED wafer structure by a KrF excimer laser at 248 nm wavelength with the laser fluence of 0.6 J/cm2 and transferring it onto a Cu substrate.