scholarly journals Enhancing light extraction mechanisms of GaN-based light-emitting diodes through the integration of imprinting microstructures, patterned sapphire substrates, and surface roughness

2010 ◽  
Vol 18 (S4) ◽  
pp. A489 ◽  
Author(s):  
Yeeu-Chang Lee ◽  
Ching-Huai Ni ◽  
Chih-Yeeu Chen
Keyword(s):  
Surface Roughness ◽  
Light Emitting Diodes ◽  
Light Extraction ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Extraction Mechanisms ◽  
Patterned Sapphire Substrates

Light Extraction Enhancement of GaN-Based Light-Emitting Diodes Using Crown-Shaped Patterned Sapphire Substrates

2012 ◽  
Vol 24 (14) ◽  
pp. 1212-1214 ◽  
Author(s):  
Ching-Hsueh Chiu ◽  
Lung-Hsing Hsu ◽  
Chia-Yu Lee ◽  
Chien-Chung Lin ◽  
Bo-Wen Lin ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Extraction ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

scholarly journals Effect of Top-Region Area of Flat-Top Pyramid Patterned Sapphire Substrate on the Optoelectronic Performance of GaN-Based Light-Emitting Diodes

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Hsu-Hung Hsueh ◽  
Sin-Liang Ou ◽  
Yu-Che Peng ◽  
Chiao-Yang Cheng ◽  
Dong-Sing Wuu ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Light Emitting Diodes ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
X Ray Diffraction ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

The flat-top pyramid patterned sapphire substrates (FTP-PSSs) have been prepared for the growth of GaN epilayers and the fabrication of lateral-type light-emitting diodes (LEDs) with an emission wavelength of approximately 470 nm. Three kinds of FTP-PSSs, which were denoted as FTP-PSS-A, FTP-PSS-B, and FTP-PSS-C, respectively, were formed through the sequential wet etching processes. The diameters of circle areas on the top regions of these three FTP-PSSs were 1, 2, and 3 μm, respectively. Based on the X-ray diffraction results, the full-width at half-maximum values of rocking curves at (002) plane for the GaN epilayers grown on conventional sapphire substrate (CSS), FTP-PSS-A, FTP-PSS-B, and FTP-PSS-C were 412, 238, 346, and 357 arcsec, while these values at (102) plane were 593, 327, 352, and 372 arcsec, respectively. The SpeCLED-Ratro simulation results reveal that the LED prepared on FTP-PSS-A has the highest light extraction efficiency than that of the other devices. At an injection current of 350 mA, the output powers of LEDs fabricated on CSS, FTP-PSS-A, FTP-PSS-B, and FTP-PSS-C were 157, 254, 241, and 233 mW, respectively. The results indicate that both the crystal quality of GaN epilayer and the light extraction of LED can be improved via the use of FTP-PSS, especially for the FTP-PSS-A.

Light Extraction Enhancement of GaN-Based Light-Emitting Diodes Using Volcano-Shaped Patterned Sapphire Substrates

2010 ◽  
Vol 49 (4) ◽  
pp. 042102 ◽  
Author(s):  
Jae Bum Kim ◽  
Sang-Mook Kim ◽  
Young Woo Kim ◽  
Sung-Ku Kang ◽  
Seong-Ran Jeon ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Extraction ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

Light extraction mechanisms in surface-textured light-emitting diodes

2001 ◽  
Author(s):  
Reiner Windisch ◽  
Stefan Meilnschmidt ◽  
Cathleen Rooman ◽  
Lars Zimmermann ◽  
Barundeb Dutta ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Extraction ◽  
Light Emitting ◽  
Extraction Mechanisms

scholarly journals Suppressing the Initial Growth of Sidewall GaN by Modifying Micron-Sized Patterned Sapphire Substrate with H3PO4-Based Etchant

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 622 ◽  
Author(s):  
Wen-Yang Hsu ◽  
Yuan-Chi Lian ◽  
Pei-Yu Wu ◽  
Wei-Min Yong ◽  
Jinn-Kong Sheu ◽  
...  
Keyword(s):  
Sapphire Substrate ◽  
Light Emitting Diodes ◽  
Ex Situ ◽  
Initial Growth ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

Micron-sized patterned sapphire substrates (PSS) are used to improve the performance of GaN-based light-emitting diodes (LEDs). However, the growth of GaN is initiated not only from the bottom c-plane but also from the sidewall of the micron-sized patterns. Therefore, the coalescence of these GaN crystals creates irregular voids. In this study, two kinds of nucleation layers (NL)—ex-situ AlN NL and in-situ GaN NL—were used, and the growth of sidewall GaN was successfully suppressed in both systems by modifying the micron-sized PSS surface.

scholarly journals Enhanced light extraction of nonpolar a-plane (11-20) GaN light emitting diodes on sapphire substrates by photo-enhanced chemical wet etching

2010 ◽  
Vol 18 (9) ◽  
pp. 9728 ◽  
Author(s):  
Younghun Jung ◽  
Jihyun Kim ◽  
Soohwan Jang ◽  
Kwang Hyeon Baik ◽  
Yong Gon Seo ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Wet Etching ◽  
Light Extraction ◽  
Light Emitting ◽  
Sapphire Substrates

Light-extraction mechanisms in high-efficiency surface-textured light-emitting diodes

2002 ◽  
Vol 8 (2) ◽  
pp. 248-255 ◽  
Author(s):  
R. Windisch ◽  
C. Rooman ◽  
B. Dutta ◽  
A. Knobloch ◽  
G. Borghs ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
Light Extraction ◽  
Light Emitting ◽  
Extraction Mechanisms
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