scholarly journals SiO2Nanopillars on Microscale Roughened Surface of GaN-Based Light-Emitting Diodes by SILAR-Based Method

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
X. F. Zeng ◽  
S. C. Shei ◽  
S. J. Chang

We reported the SiO2nanopillars on microscale roughened surface on GaN-based LED to enhance light-extraction efficiency. ZnO nanoparticles were deposited on SiO2as an etching mask before ICP etching SiO2by successive ionic layer adsorption and reaction method (SILAR), and the different heights of SiO2nanopillars on microroughened ITO/GaN were obtained after etching. Compared to a regular (flat surface) GaN-based LED, the light output power for a LED with microroughening was increased by 33%. Furthermore, the proposed LEDs with SiO2nanopillars on microroughened surface show the enhancement in light output power by 42.7%–49.1% at 20 mA. The increase in light output power is mostly attributed to reduction in Fresnel reflection by rough surface. The height of SiO2nanopillars was increasing cause resulting in more rough on the microscale surface of GaN-based LEDs.

2009 ◽  
Vol 30 (11) ◽  
pp. 1152-1154 ◽  
Author(s):  
Hung-Wen Huang ◽  
Chung-Hsiang Lin ◽  
Zhi-Kai Huang ◽  
Kang-Yuan Lee ◽  
Chang-Chin Yu ◽  
...  

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 319 ◽  
Author(s):  
Bin Tang ◽  
Jia Miao ◽  
Yingce Liu ◽  
Hui Wan ◽  
Ning Li ◽  
...  

Current solutions for improving the light extraction efficiency of flip-chip light-emitting diodes (LEDs) mainly focus on relieving the total internal reflection at sapphire/air interface, but such methods hardly affect the epilayer mode photons. We demonstrated that the prism-structured sidewall based on tetramethylammonium hydroxide (TMAH) etching is a cost-effective solution for promoting light extraction efficiency of flip-chip mini-LEDs. The anisotropic TMAH etching created hierarchical prism structure on sidewall of mini-LEDs for coupling out photons into air without deteriorating the electrical property. Prism-structured sidewall effectively improved light output power of mini-LEDs by 10.3%, owing to the scattering out of waveguided light trapped in the gallium nitride (GaN) epilayer.


2011 ◽  
Vol 1342 ◽  
Author(s):  
Atsushi Nishikawa ◽  
Naoki Furukawa ◽  
Dong-gun Lee ◽  
Kosuke Kawabata ◽  
Takanori Matsuno ◽  
...  

ABSTRACTWe investigated the electroluminescence (EL) properties of Eu-doped GaN-based light-emitting diodes (LEDs) grown by organometallic vapor phase epitaxy (OMVPE). The thickness of the active layer was varied to increase the light output power. With increasing the active layer thickness, the light output power monotonically increased. The maximum light output power of 50 μW was obtained for an active layer thickness of 900 nm with an injected current of 20 mA, which is the highest value ever reported. The corresponding external quantum efficiency was 0.12%. The applied voltage for the LED operation also increased with the active layer thickness due to an increase in the resistance of the LED. Therefore, in terms of power efficiency, the optimized active layer thickness was around 600 nm. These results indicate that the optimization of the LED structure would effectively improve the luminescence properties.


2015 ◽  
Vol 15 (4) ◽  
pp. 454-461 ◽  
Author(s):  
Mumta Hena Mustary ◽  
Beo Deul Ryu ◽  
Min Han ◽  
Jong Han Yang ◽  
Volodymyr V. Lysak ◽  
...  

2009 ◽  
Author(s):  
J. K. Huang ◽  
H. W. Huang ◽  
C. H. Lin ◽  
K. Y. Lee ◽  
C. C. Yu ◽  
...  

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