Improved extraction efficiency of light-emitting diodes by modifying surface roughness with anodic aluminum oxide film

被引：20

作者：

Wang, Chien-Chun ^{[1
]}

Lu, Hung-Chi ^{[2
]}

Liu, Chien-Chih ^{[3
]}

Jenq, Fenq-Lin ^{[4
]}

Wang, Yeong-Her ^{[1
]}

Houng, Mau-Phon ^{[2
]}

机构：

[1] Natl Cheng Kung Univ, Inst Electroopt Sci & Engn, Tainan 701, Taiwan

[2] Natl Cheng Kung Univ, Dept Elect Engn, Inst Microelect, Tainan 701, Taiwan

[3] Nan Jeon Inst Technol, Dept Elect Engn, Tainan 73746, Taiwan

[4] Far E Univ, Dept Elect Engn, Tainan 744, Tainan County, Taiwan

来源：

IEEE PHOTONICS TECHNOLOGY LETTERS | 2008年 / 20卷 / 5-8期

关键词：

anodic alumina oxide (AAO); external quantum efficiency; light-emitting diodes (LEDs); light extraction; nano-roughened;

D O I：

10.1109/LPT.2008.916948

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

An anodic alumina oxide (AAO) film with nanoroughening is added on the top window layer of AlGaInP light-emitting diodes (LEDs) to improve the light extraction of the device. The AAO film has a natural porosity to provide light scattering centers at the surface, allowing an increase of light emission intensity with no loss of or damage to the semiconductor material. Further, the fabricated AAO film with a refractive index is about n = 1.7 which is intermediate between those of air and the window layer of GaP. By inserting this layer between the ambient and GaP, it broadens the critical angle for light emission and reduces internal reflection. Experiments with laboratory-fabricated AlGaInP devices of conventional design demonstrated a 32% improvement in the luminous intensity at 20 mA for the device with the AAO layer. This letter shows by theory and experiment that AAO films can be used as a low-cost, easily implemented surface nano-roughening for improving extraction efficiency of AlGaInP LEDs.

引用

页码：428 / 430

页数：3

共 16 条

[1] Theoretical demonstration of enhancement of light extraction of flip-chip GaN light-emitting diodes with photonic crystals [J].

Chao, Chia-Hsin ;

Chuang, S. L. ;

Wu, Tzong-Lin .

APPLIED PHYSICS LETTERS, 2006, 89 (09)

[2]

Ditchburn R. W, 1963, LIGHT, P582

[3] Enhancement of the light output of GaN-based ultraviolet light-emitting diodes by a one-dimensional nanopatterning process [J].

Hong, HG ;

Kim, SS ;

Kim, DY ;

Lee, T ;

Song, JO ;

Cho, JH ;

Sone, C ;

Park, Y ;

Seong, TY .

APPLIED PHYSICS LETTERS, 2006, 88 (10)

[4] Enhancement in light output of InGaN-based microhole array light-emitting diodes [J].

Hsueh, TH ;

Shen, JK ;

Huang, HW ;

Chu, JY ;

Kao, CC ;

Kuo, HC ;

Wang, SC .

IEEE PHOTONICS TECHNOLOGY LETTERS, 2005, 17 (06) :1163-1165

[5] Investigation of InGaN/GaN light emitting diodes with nano-roughened surface by excimer laser etching method [J].

Huang, Hung-Wen ;

Kao, Chih-Chiang ;

Chu, Jung-Tang ;

Wang, Wei-Chih ;

Lu, Tien-Chang ;

Kuo, Hao-Chung ;

Wang, Shing-Chung ;

Yu, Chang-Chin ;

Kuo, Shou-Yi .

MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 2007, 136 (2-3) :182-186

[6] Improved light-output and electrical performance of InGaN-based, light-emitting diode by microroughening of the p-GaN surface [J].

Huh, C ;

Lee, KS ;

Kang, EJ ;

Park, SJ .

JOURNAL OF APPLIED PHYSICS, 2003, 93 (11) :9383-9385

[7]

JENKINS FA, 1976, FUNDAMENTALS OPTICS, P472

[8] Light-output enhancement in a nitride-based light-emitting diode with 22° undercut sidewalls [J].

Kao, CC ;

Kuo, HC ;

Huang, HW ;

Chu, JT ;

Peng, YC ;

Hsieh, YL ;

Luo, CY ;

Wang, SC ;

Yu, CC ;

Lin, CF .

IEEE PHOTONICS TECHNOLOGY LETTERS, 2005, 17 (01) :19-21

[9] Mechanical stability of a flexible ferroelectric liquid crystal display with a periodic array of columnar spacers [J].

Kim, DW ;

Yu, CJ ;

Lim, YW ;

Na, JH ;

Lee, SD .

APPLIED PHYSICS LETTERS, 2005, 87 (05)

[10] High-power truncated-inverted-pyramid (AlxGa1-x)0.5In0.5P/GaP light-emitting diodes exhibiting >50% external quantum efficiency [J].

Krames, MR ;

Ochiai-Holcomb, M ;

Höfler, GE ;

Carter-Coman, C ;

Chen, EI ;

Tan, IH ;

Grillot, P ;

Gardner, NF ;

Chui, HC ;

Huang, JW ;

Stockman, SA ;

Kish, FA ;

Craford, MG ;

Tan, TS ;

Kocot, CP ;

Hueschen, M ;

Posselt, J ;

Loh, B ;

Sasser, G ;

Collins, D .

APPLIED PHYSICS LETTERS, 1999, 75 (16) :2365-2367

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