S1660104 Optimal design of the patterned sapphire substrate from viewpoints of light extraction efficiency and crystalline quality of light emitting diodes

2014 ◽  
Vol 2014 (0) ◽  
pp. _S1660104--_S1660104-
Author(s):  
Ryo Inomoto ◽  
Narihito Okada ◽  
Kazuyuki Tadatomo
Keyword(s):  
Optimal Design ◽  
Sapphire Substrate ◽  
Light Emitting Diodes ◽  
Extraction Efficiency ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Crystalline Quality ◽  
Patterned Sapphire Substrate ◽  
Light Emitting

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.

Improved Light Extraction Efficiency of Light-Emitting Diode Grown on Nanoscale-Silicon-Dioxide-Patterned Sapphire Substrate

2020 ◽  
Vol 12 (5) ◽  
pp. 647-651 ◽  
Author(s):  
Young Hoon Sung ◽  
Jaemin Park ◽  
Eun-Seo Choi ◽  
Hee Chul Lee ◽  
Heon Lee
Keyword(s):  
Silicon Dioxide ◽  
Sapphire Substrate ◽  
Extraction Efficiency ◽  
Light Emitting Diode ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Sapphire Wafer ◽  
Luminescence Efficiency

A conical-shaped Si dioxide nano-pattern was employed to sapphire substrate in order to improve the light extraction efficiency of light-emitting diodes. The conical-shaped Si dioxide nano-patterns were fabricated on a 2-inch sapphire wafer using direct imprinting of hydrogen silsesquioxane material. A blue-LED structure was grown on conical-shaped silicon-dioxide nano-patterned sapphire substrates. Photoluminescence and electroluminescence measurements were used to confirm the effectiveness of the nanoscale Si oxide patterned sapphire. An improvement in the luminescence efficiency was observed when nanoscale Si oxide patterned sapphire substrate was used. 1.5 times higher PL intensity and 1.6 times higher EL intensity were observed for GaN LED structure grown on nanoscale Si oxide patterned sapphire, compared to LED structure grown on conventional flat sapphire wafer.

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