TY - JOUR
T1 - Improved extraction efficiency of light-emitting diodes by wet-etching modifying AZO surface roughness
AU - Kuo, Ting Wei
AU - Lin, Shi Xiong
AU - Hung, Yueh Yu
AU - Horng, Jui Hong
AU - Houng, Mau Phon
N1 - Funding Information:
Manuscript received October 28, 2010; revised December 20, 2010; accepted January 01, 2011. Date of publication January 13, 2011; date of current version March 04, 2011. This work was supported by the National Science Council of Taiwan under Contract NSC-97-2221-E-0 06-239-MY2. T.-W. Kuo, S.-X. Lin, Y.-Y. Hung, and M.-P. Houng are with the Institute of Microelectronics, Department of Electrical Engineering, National Cheng-Kung University, Tainan 701, Taiwan (e-mail: [email protected]). J.-H. Horng is with the Department of Mechanical and Marine Engineering, National Taiwan Ocean University, Keelung 70101, Taiwan. Color versions of one or more of the figures in this letter are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/LPT.2011.2105863
PY - 2011
Y1 - 2011
N2 - In this letter, the AlGaInP light-emitting diodes (LEDs) between the air and GaP layer are added to the textured ZnO:Al (AZO) films in order to improve light extraction of the device. At 20 mA, the relative luminous intensity of textured AZO LEDs is increased by 129.9% when compared with the conventional sample. Furthermore, the far-field radiation pattern was improved with intensity not only at 0°, but also from 60° to 300°. Due to loss of internal Fresnel efficiency and critical angle efficiency, textured AZO LEDs are significantly improved by the wet-etching technique. The surface treatment of AZO films generates surface texturing that is characterized as random crater. It presents a better far-field radiation pattern when compared with nontextured AZO films. This letter has demonstrated the far-field radiation pattern and the theory for enhancing light emission efficiency of LEDs.
AB - In this letter, the AlGaInP light-emitting diodes (LEDs) between the air and GaP layer are added to the textured ZnO:Al (AZO) films in order to improve light extraction of the device. At 20 mA, the relative luminous intensity of textured AZO LEDs is increased by 129.9% when compared with the conventional sample. Furthermore, the far-field radiation pattern was improved with intensity not only at 0°, but also from 60° to 300°. Due to loss of internal Fresnel efficiency and critical angle efficiency, textured AZO LEDs are significantly improved by the wet-etching technique. The surface treatment of AZO films generates surface texturing that is characterized as random crater. It presents a better far-field radiation pattern when compared with nontextured AZO films. This letter has demonstrated the far-field radiation pattern and the theory for enhancing light emission efficiency of LEDs.
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U2 - 10.1109/LPT.2011.2105863
DO - 10.1109/LPT.2011.2105863
M3 - Article
AN - SCOPUS:79952401375
SN - 1041-1135
VL - 23
SP - 362
EP - 364
JO - IEEE Photonics Technology Letters
JF - IEEE Photonics Technology Letters
IS - 6
M1 - 5686915
ER -