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

scholarly journals Performance of InGaN Light-Emitting Diodes Fabricated on Patterned Sapphire Substrates with Modified Top-Tip Cone Shapes

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hsu-Hung Hsueh ◽  
Sin-Liang Ou ◽  
Chiao-Yang Cheng ◽  
Dong-Sing Wuu ◽  
Ray-Hua Horng
Keyword(s):  
Light Emitting Diodes ◽  
Substrate Surface ◽  
Light Output ◽  
Chemical Vapor ◽  
Wet Etching ◽  
Light Output Power ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Patterned Sapphire Substrates

InGaN light-emitting diodes (LEDs) were fabricated on cone-shaped patterned sapphire substrates (PSSs) by using low-pressure metalorganic chemical vapor deposition. To enhance the crystal quality of the GaN epilayer and the optoelectronic performance of the LED device, the top-tip cone shapes of the PSSs were further modified using wet etching. Through the wet etching treatment, some dry-etched induced damage on the substrate surface formed in the PSS fabrication process can be removed to achieve a high epilayer quality. In comparison to the LEDs prepared on the conventional sapphire substrate (CSS) and cone-shaped PSS without wet etching, the LED grown on the cone-shaped PSS by performing wet etching for 3 min exhibited 55% and 10% improvements in the light output power (at 350 mA), respectively. This implies that the modification of cone-shaped PSSs possesses high potential for LED applications.

Improvement of GaN-based light emitting diodes performance grown on sapphire substrates patterned by wet etching

2007 ◽  
Author(s):  
Haiyong Gao ◽  
Fawang Yan ◽  
Yang Zhang ◽  
Jinmin Li ◽  
Yiping Zeng ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Wet Etching ◽  
Light Emitting ◽  
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.

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