Elimination of total internal reflection in GaInN light-emitting diodes by graded-refractive-index micropillars

Journal Article · Mon Dec 01 00:00:00 EST 2008 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3041644· OSTI ID:21175790

Kim, Jong Kyu; Noemaun, Ahmed N; Mont, Frank W; Meyaard, David; Schubert, E Fred ^[1]; Poxson, David J ^[2]; Kim, Hyunsoo; Sone, Cheolsoo; Park, Yongjo ^[3]

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1. Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
2. Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
3. Central R and D Institute, Samsung Electro-Mechanics, Suwon 443-743 (Korea, Republic of)

A method for enhancing the light-extraction efficiency of GaInN light-emitting diodes (LEDs) by complete elimination of total internal reflection is reported. Analytical calculations show that GaInN LEDs with multilayer graded-refractive-index pillars, in which the thickness and refractive index of each layer are optimized, have no total internal reflection. This results in a remarkable improvement in light-extraction efficiency. GaInN LEDs with five-layer graded-refractive-index pillars, fabricated by cosputtering TiO{sub 2} and SiO{sub 2}, show a light-output power enhanced by 73% and a strong side emission, consistent with analytical calculations and ray-tracing simulations.

• OSTI ID: 21175790
• Journal Information: Applied Physics Letters, Vol. 93, Issue 22; Other Information: DOI: 10.1063/1.3041644; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DEPOSITION
GALLIUM NITRIDES
INDIUM NITRIDES
LAYERS
LIGHT EMITTING DIODES
REFLECTION
REFRACTIVE INDEX
SEMICONDUCTOR MATERIALS
SILICON OXIDES
SPUTTERING
TITANIUM OXIDES