Chun J.,Gwangju Institute of Science and Technology |
Lee K.J.,Gwangju Institute of Science and Technology |
Leem Y.-C.,Gwangju Institute of Science and Technology |
Kang W.-M.,Gwangju Institute of Science and Technology |
And 5 more authors.
ACS Applied Materials and Interfaces | Year: 2014
We report on the vertically stacked color tunable light-emitting diodes (LEDs) fabricated using wafer bonding with an indium tin oxide (ITO) layer and transfer printing by the laser lift-off process. Employing optically transparent and electrically conductive ITO as an adhesion layer enables to bond the GaN-based blue and AlGaInP-based yellow LEDs. We find out that the interdiffusion of In, O, and Ga at the interface between ITO and GaP allows the strong bonding of the heterogeneous optoelectronic materials and the integration of two different color LEDs on a single substrate. The efficacy of this method is demonstrated by showing the successful control of color coordinate from the vertically stacked LEDs by modulating the individual intensity of blue and yellow emissions. (Graph Presented). © 2014 American Chemical Society.
Oh H.S.,Korea Photonics Technology Institute |
Ryu H.-S.,Korea Photonics Technology Institute |
Ryu H.-S.,Sunchon National University |
Park S.H.,Korea Photonics Technology Institute |
And 6 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2015
We investigated air gap-induced hybrid distributed Bragg reflectors (AH-DBRs) for use in high brightness and reliable AlGaInP-based light emitting diodes (LEDs). An air gap was inserted into the side of DBRs by selectively etching the AlxGa1-xAs DBR structures. With the AH-DBR structures, the optical output power of LEDs was enhanced by 15% compared to LEDs having conventional DBRs, due to the effective reflection of obliquely incident light by the air gap structures. In addition, the electrical characteristics showed that the AH-DBR LED is a desirable structure for reducing the leakage current, as it suppresses unwanted surface recombinations. Copyright © 2015 American Scientific Publishers
Ahn S.-C.,Institute of Photonic Technology |
Lee B.-T.,Chonnam National University |
An W.-C.,Jeonju University |
Kim D.-K.,AUK Corporation |
And 3 more authors.
Journal of the Korean Physical Society | Year: 2016
In this paper, a distributed Bragg reflector (DBR) for a bottom reflector in 850-nm GaAs infrared light-emitting diodes (Ir-LEDs) was developed and optimized. At an 850-nm wavelength, markedly improved reflection spectra were observed from DBRs consisting of Al1-xGaxAs/AlxGa1-xAs materials. In addition, the reflection spectra of Al1-xGaxAs/AlxGa1-xAs-based DBRs was found to increase with increasing difference between the high and the low refractive indices. At multiple layers of 10 pairs, maximal reflection spectra having about a 92% reflectivity were obtained from DBRs consisting of GaAs/AlAs. At 20 pairs, however, outstanding reflection spectra having a higher reflectivity and broader width were clearly observed from DBRs consisting of Al0.1Ga0.9As/Al0.9Ga0.1As. Some incident light appears to have been absorbed and confined by the narrow bandgap of the GaAs material used in DBRs consisting of GaAs/AlAs. This fact could be supported by the decrease in the reflectivity of the shorter wavelength region in DBRs consisting of GaAs/AlAs. For this reason, a remarkable output power could be obtained from the 850-nm GaAs Ir-LED chip having a DBR consisting of Al0.1Ga0.9As/Al0.9Ga0.1As. © 2016, The Korean Physical Society.
Oh H.S.,Korea Photonics Technology Institute KOPTI |
Park S.H.,Korea Photonics Technology Institute KOPTI |
Kim Y.J.,AUK corporation |
Lee H.J.,AUK corporation |
Cho Y.D.,AUK corporation
Asia Communications and Photonics Conference, ACP | Year: 2013
Recently, AlGaInP-based light emitting diodes (LEDs) have experienced an impressive evolution in both device performance and market volume. However, development of new applications is required in order to realize their full potential in areas such as use as a light source for auto focusing in digital cameras, special illumination for particular functions in agriculture, and in full color displays. To enlarge their utility in these applications, it is necessary to fabricate and understand a new structure capable of emitting longer wavelengths of around 700 nm. In particular, AlGaInP heterostructure LEDs are lattice-matched with respect to the GaAs substrate, which limits the emitting spectrum to around 650 nm at the longer peak wavelength side. To fabricate an LED structure capable of emitting at a 700 nm peak wavelength, the composition (x) of GaxIn1-xP material in the active layer requires a compressive strain of larger than 1 %. This large lattice mismatch, however, causes significant problems in terms of both growth and device properties due to the formation of defects. To overcome these problems, it is necessary to relieve the well strain via the formation of islands, referred to as a Stranski-Krastanow (S-K) growth mode, in order to prevent the generation of dislocations [1,2]. However, in AlGaInP-based LEDs emitting at a 700 nm peak wavelength, the effects of well strain on the epitaxial growth and the realization of device performance has yet to be extensively studied. In this study, we investigate the behaviors of morphological and optical characteristics on the composition of Ga0.33In0.67P material and demonstrate the performance of a device emitting at around 700 nm using quantum dot (QD)-based LEDs. © OSA 2013.
Lee H.J.,AUK Corporation |
Kim J.H.,Wonkwang University |
Lee C.H.,Wonkwang University
ECS Journal of Solid State Science and Technology | Year: 2015
The effects of using an n-AlGaAs layer to improve the efficiency of wafer-bonded reflective 590 nm AlGaInP light-emitting diodes (LEDs) were investigated. This n-AlGaAs layer was grown on an optically absorbing substrate using metal organic chemical vapor deposition (MOCVD) during AlGaInP LED epitaxial growth. It was found that the inserted n-AlGaAs layer effectively acted as both an etching stop layer and ohmic contact layer. Here, the n-AlGaAs layer was located on the top layer of the reflective AlGaInP LED. As a result, a 1.2-fold relative increase in output power was observed from the reflective AlGaInP LED chip having the n-AlGaAs top layer. This increase was subsequently attributed to the increase in the current spreading effect due to insertion of the n-AlGaAs layer. © 2015 The Electrochemical Society. All rights reserved.
Kim J.H.,Wonkwang University |
Lee H.J.,AUK Corporation
Materials Letters | Year: 2014
The characteristics of AlGaAs films grown directly on a lattice-mismatched Al2O3 substrate were investigated. Metal organic chemical vapor deposition based AlGaAs films were grown on a transparent Al 2O3 substrate, using a GaAs film as the buffer layer for the post-growth of the AlGaAs film. It was found that a higher Al composition in AlGaAs film on the Al2O3 substrate was observed when GaAs buffer layer was thermally treated. Notably, a resistivity of 0.018 Ω/cm was obtained from the AlGaAs film grown on the Al2O3 substrate, almost equivalent to that for GaAs substrate. These results thus support the position that AlGaAs films grown on a transparent Al 2O3 substrate can be attractive for use in solar cells or light-emitting diodes. © 2014 Elsevier B.V.
Lee H.J.,AUK Corporation |
Kim Y.J.,AUK Corporation |
Kim S.U.,AUK Corporation |
Jo J.U.,LG Corp |
And 3 more authors.
Japanese Journal of Applied Physics | Year: 2013
Metal organic chemical vapor deposition (MOCVD) based aluminum gallium arsenide (AlGaAs) used as the bottom window (BW), which was inserted between the light-emitting diode (LED) structure and the absorbing substrate, has been proposed to improve the extraction efficiency of 630nm AlGaInP LEDs. In an AlGaInP LED with this AlGaAs BW, enhanced light extraction efficiency was observed, as some of the light emitted from the active region to the absorbing substrate could pass out of the LED through the BW. In addition, it was found that a output power of 8mW was obtained from an AlGaInP LED with both a BW and a distribution Bragg reflector (DBR), a nearly two fold improvement of over 4.2mW that was obtained from a conventional one at an injection current of 80 mA. © 2013 The Japan Society of Applied Physics.
AUK Corporation | Date: 2014-07-18
The present invention relates to a high-efficiency AlGaInP light-emitting diode directly grown on a transparent substrate and a method of manufacturing the same, and, more particularly, to a high-efficiency AlGaInP light-emitting diode grown on a sapphire substrate and a method of manufacturing the same. According to the present invention, an AlGaInP light-emitting diode is manufactured using an inexpensive sapphire substrate having high transmittance to ultraviolet rays, infrared rays and visible rays. The AlGaInP light-emitting diode according to the present invention can emit light with high efficiency because a lower substrate does not absorb light, and can be effectively manufactured because a process of removing a GaAs or a process of bonding a sapphire substrate is not conducted.
a UK company | Date: 2011-05-10
Audio and video tapes, and discs, namely, audio and video tapes and audio and video recordings in the form of discs, DVDs, DVD-ROM, CD-ROM, compact discs, laser discs, floppy discs, hard discs, optical discs, pre-recorded magnetic data carriers, phonograph records, magnetic and digital tapes, all featuring music, musical sound recordings, musical video recordings and video recordings featuring cartoon characters, optionally also with live action sequences or images; jackets for video cassettes; prerecorded compact discs and pre-recorded video tapes relating to childrens entertainment and education; films, namely, animated films, live action films, short films and feature films, all featuring musical sound recordings, musical video recordings and video recordings featuring cartoon characters with live action sequences and images; phonograph records featuring music, speech, or educational or entertainment materials, namely, childrens educational material, reading educational material and music; motion picture films, sound recordings and video recordings, featuring comedy, dramatic, documentary, musical, educational or entertainment materials, namely, childrens educational material, reading educational material and music; electronic downloadable publications, namely, books, comics, magazines, newsletters, journals, pamphlets, brochures, booklets and a series of fiction or non-fiction books all featuring childrens entertainment; downloadable software, namely, for the display,organization, transmission, reception or searching of educational or entertainment information, music, sounds, images, text, musical, musical sound recordings, musical video recordings and video recordings all featuring cartoon characters, optionally also with live action sequences or images downloadable from the Internet; blank magnetic computer audio and video tapes, cassettes and cartridges; radios; radios for use in the shower; audio cassette recorders; videocassette recorders; compact disc players; MP3 players; karaoke machines, namely, audio components for use in karaoke, namely, compact disc players, audio amplifiers, audio mixers, microphones, audio speakers, and cables for use with audio components; cameras; projectors, namely, movie projector and slide projector; calculators; sunglasses; office requisites, namely, computer mouse mats and computer wrist mats; video games, namely, interactive video games software, pre-recorded video games CDs, tapes, cassettes, discs and cartridges; video game machines for use with televisions; electronic amusement apparatus for use with television receivers, namely, computer game hardware and peripherals; computer game programs; electronic computer game programs downloadable from the Internet; computer software for the display, organization, transmission, reception or searching of educational or entertainment information; magnets, novelty magnets, refrigerator magnets; cell phones; snorkels; bicycle helmets, football helmets, baseball and softball batting helmets, skateboard helmets, ski helmets, snowboarding helmets; goggles for skiing, swimming, racket sports, or sledding; swimming aids, namely, life jackets; nose plugs for swimming. Books and magazines, all for children; comic books, comic strips in general; childrens activity books, childrens pop-up books; printed matter, namely, magazines, journals, pamphlets, brochures, booklets and a series of fiction or non-fiction books, all featuring childrens entertainment; coloring books; bookmarks of paper or card; books, childrens books featuring interactive magnetic or felt elements; posters; paper banners; mounted photographs, unmounted photographs; postcards; printed charts of paper or card such as growth charts, space charts, alphabet charts, and multiplication charts; greeting cards, blank cards, Christmas cards, giftcards, note cards; wrapping paper; paper tags; paper and cardboard bags and boxes for packaging; cardboard and cardboard articles, namely, cartons and containers; packing paper; paper ribbons; paper gift wrapping ribbons; stationery, notepaper, envelopes, note books; blank, printed or partially printed paper labels; address labels; loose leaf binders; exercise books; writing pads; address books; pens, pencils, pencil cases, pen cases; pencil holders; stationery boxes; artists materials, namely, artists pencils, artists brushes, artists pens, stencils, poster art sets, paint boxes, paint brushes, drawing materials, namely, instruments, pads and paper; coloring materials, namely, crayons, felt tip pens, coloring pencils, marker pens, highlighters and brush pens, ink pens; adhesives for stationery or household purposes; modeling materials and compounds for use by children; modeling clay; modeling compounds; stamp pads and ink therefore; writing ink, rubber commemorative stamps; printed tickets; printed souvenir programs, flyers, posters, leaflets, brochures, pamphlets and booklets commemorating charitable events; printed instructional, educational and teaching material all for use with infants, babies and children; flashcards; printed teaching materials in the form of games for use in the fields of mathematics, language arts, social studies, art, music, theatre arts or literature; stickers; paper and plastic transfers, namely, rub-on, stick-on and iron-on temporary tattoos, decalcomanias, iron-on transfers; stencils; paper and plastic transparencies; calendars; tear-off calendars; diaries; office requisites, namely, type correcting fluid, punches, rubber bands, paper clips, binder clips and fasteners, staplers, adhesive tape dispensers, erasers, pencil sharpeners, note binders, namely, paper fasteners, loose leaf binders, three-ring binders, mechanical binder sets comprising rings; files, namely, document files, card files, file folders and file sorters; folders; memo pads; electric typewriters; printing blocks; receptacles for holding rubber bands, paper clips, binder clips and paper fasteners; disposable diapers; paper bibs; paper napkins and paper tablecloths; bathroom tissue; facial tissues; paper handkerchiefs; absorbent paper for use in the kitchen; paper towels; paper face towels; table mats made of paper; and paper place mats; coasters made of paper; plastic sandwich bags; general purpose plastic and paper bags; plastic and paper garbage bags; photo, scrap, coin and stamp albums; scrapbooks; almanacs; announcement cards; blackboards; blotters; book ends; bookmarks; bottle wrappers of cardboard or paper; paper and cardboard boxes; trading cards and trivia cards; printed charts; book bindings; embroidery design patterns; printed dress making patterns; paper mache figurines; paper flags; paper flower pot covers; construction paper; craft paper; loose leaf paper; tissue paper; tracing paper; checkbook covers; passport holders; book covers; personal organizers; pocket secretaries; chalk boards and easels for home or school use; wooden book ends. Clothing for adults and children, namely, t-shirts and sweatshirts, footwear, slippers, flip flops, sports shoes, basketball shoes, tennis shoes, boots, beach sandals, rain boots, ski boots; shirts, pants, jeans, dungarees, sweaters; fleece tops, namely, pullovers, vests, sweatshirts; blouses; jackets; trousers; ties; shorts; socks; belts; scarves; suits; coats; vest; dresses; skirts; miniskirts; leggings; nightwear; pajamas; shorts; nightdresses; singlets; fleece dressing gowns; dressing gowns made of terry cloth or cotton; tracksuits, training suits, sweat pants; hooded tops, namely, pullovers, vests, sweatshirts; zip up jogging suits; headwear, namely, caps and hats; headbands; overalls; cardigans; gloves; over-coats; underwear; boxer shorts; bras; briefs; camisoles; bodysuits; swimwear; toweling robes; eye masks, namely, sleep masks of fabric; babies and infants clothes, namely, bibs made of cloth, t-shirts for babies, and romper suits; aprons; tabards; gardening aprons; costumes, namely, party costumes for childrens occasions, namely, parties, live-stage events, open air events, Halloween and masquerades, costumes for live events, namely, fancy-dress costumes, childrens character merchandising shows, dance and role-playing; belts as parts of clothes; suspenders; plastic baby bibs; bathing caps. Figures representing cartoon characters; games and playthings, namely, soft-sculpture toys; wooden toys, namely, building blocks, alphabet blocks and pull out wooden puzzles; electrical and mechanical action toys; electronic action toys; radio controlled toys; swimming aids, namely, pool rings, arm floats for recreational use, kick board flotation device for recreational use, swim rings, floating recreational lounge chairs, air beds, namely, inflatable float mattresses for recreational use; inflatable ride-on toys; swim fins; beach balls; paddling pools, namely, play swimming pools; play mats containing infant toys; dolls; action figures and play figures; plush toys; beanbag toys; stuffed toy animals; toy figures; puppet toys for babies and infants, namely, rattles, mobiles, play quilts as doll accessory and multiple activity toys; toys designed to be attached to car seats, strollers, cribs, high chairs; play sets designed to interact with dolls, play figures and action figures; make-believe sets, namely, play houses and play tea sets; vehicles for dolls, action figures and play figures; carrying or collecting cases for dolls, play figures and action figures; doll clothing and accessories; childrens multiple activity toys, namely, picture activity sets comprised of felt, wipe-away sets comprised of dry erase writing boards and writing surfaces, slate boards for writing, water color boards, decorative glitter sets; childrens multiple activity toys, namely, knitting sets comprised of stitch markers, stitch gauges, stitch holders, yam bobbins, needles, and toy construction sets; jokes and novelty items, namely, paper face masks, rude noise-makers, false faces, false noses, false eyeglasses, false beards, false moustaches, windup toys, water squirting toys, magic tricks; party favors in the nature of small toys; kaleidoscopes; balloons; jigsaw puzzles, manipulative puzzles and cube-type puzzles; tic-tac-toe; domino sets; equipment sold as a unit for board, card and skill action games and floor games; Christmas tree decorations, not including confectionery or illumination articles; knee, elbow and wrist protectors for use in skating and other sports; toy vehicles; construction toys; wooden toy model train sets; ride-on toys; ride on toys, namely, pedal cars and pedal planes; toy bicycles, toy tricycles, toy scooters; gymnastic apparatus; sporting articles, namely, sport balls; tennis, squash, badminton, racquetball, paddle ball and table tennis rackets and racket covers; baseball and softball mitts; baseball and softball gloves, bats, catchers masks; leg guards for athletic use, athletic supporters and protective cups, shin, thigh, leg, hip, shoulder, rib and arm pads for athletic use; baseball and softball bases; kicking tees; field hockey and lacrosse sticks; mouth guards for athletic use; archery bows, bow strings, arrows, targets, quivers; basketball goals, nets, and backboards; croquet sets; boxing gloves; barbells; skis, ski poles; snowboards; bowling balls; golf equipment and accessories, namely, clubs, bags, golf tees, gloves, ball markers, club head covers, divot repair tools; ice hockey sticks and pucks; shuffleboard sticks; badminton shuttlecocks; volleyball, tennis, and table tennis nets; cricket sticks and wickets; snow sleds for recreational use; surf boards; body boards; skim boards; windsurfing boards; ice skates; roller skates; in-line skates; skate boards; stationery exercise bicycles; flying discs; water skis; dartboards; darts; fishing rods, reels and lures; trampolines; bounce-on inflatable toys; wooden skittles; yo-yos; skipping ropes; kites; toy phones, toy torches; arcade games; coin-operated ride-on toys; confetti; hobby craft sets consisting of felt shapes for making pictures. Television production and television program services, namely, scheduling, programming, syndication; production and distribution of radio and television programs for others; radio entertainment production; and distribution of radio and television programs for others; radio entertainment production; television show production; motion picture film and videotape production; distribution of motion pictures; rental of videotapes, cinematographic films, sound and video recordings; publication of books, magazines, journals; music publishing services; entertainment in the nature of theatre productions or live performances by a musical group; educational services for children, namely, conducting classes, workshops or seminars in the fields of language arts, mathematics, science, social studies, computer skills, family education,visual arts, theatre or music, all by means of radio or television; entertainment services, namely, on-line based computer games.
AUK Corporation | Date: 2014-01-29
The present invention relates to a light emitting diode and a method for manufacturing same, and more specifically relates to growing a GaN layer of high quality on an upper part of an AlGaInP-based light emitting diode to improve the light extraction efficiency of the light emitting diode, wherein the GaN layer has a larger band gap and a smaller refractive index than AlGaInP-based material. The AlGaInP-based light emitting diode of the present invention is characterized by forming the GaN layer on the upper surface, and the GaN layer preferably has a surface of a fine uneven pattern. The GaN layer can be grown in the same system after forming the AlGaInP-based light emitting diode without an additional process.