Study on Light Intensity Enhancement of ZnO/ITO/P-GaN Light-Emitting Diodes

2011 ◽  
Vol 130-134 ◽  
pp. 4084-4087
Author(s):  
Hsing Cheng Chang ◽  
Ya Hui Chen ◽  
San Shan Hung ◽  
Chi Chih Lai ◽  
Chein Chuan Hung ◽  
...  

Light intensity enhancement of GaN-based blue light-emitting diodes (LEDs) is performed using different surface roughening technologies. Three roughening technologies are applied that contain surface roughening of p-GaN, textured indium tin oxide (ITO) on roughened p-GaN, and growing ZnO nanorods on textured ITO/p-GaN. A roughened p-GaN surface was grown on the c-plane sapphire substrate at temperature 800 °C. The morphologies of the textured LEDs with roughness in the range from 9.67 nm to 51.13 nm were observed. The light output efficiency of LED with roughened ITO layer is increased up to 73.8 %. Different dimensions of LEDs can be driven by constant injection current 20 mA without increasing threshold voltage, and larger size of ZnO/ITO/p-GaN LED shows higher luminance intensity. The LEDs with ZnO nanorods on roughened ITO/GaN have shown great performance to enhance the power conversion efficiency.

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Young Jae Park ◽  
Hyounsuk Song ◽  
Kang Bok Ko ◽  
Beo Deul Ryu ◽  
Tran Viet Cuong ◽  
...  

The effect of ZnO nanostructures on the light output power of 375 nm near-ultraviolet light-emitting diodes (NUV-LEDs) was investigated by comparing one-dimensional (1D) nanorods (NR-ZnO) with two-dimensional (2D) nanosheets (NS-ZnO). ZnO nanostructures were grown on a planar indium tin oxide (ITO) by solution based method at low temperature of 90°C without degradation of the forward voltage. At an injection current of 100 mA, the light output efficiency of NUV-LED with NR-ZnO was enhanced by around 30% compared to the conventional NUV-LEDs without ZnO nanostructures. This improvement is due to the formation of a surface texturing, resulting in a larger escape cone and a multiple scattering for the photons in the NUV-LED, whereas the light output efficiency of NUV-LED with NS-ZnO was lower than that of the conventional NUV-LEDs due to the internal reflection and light absorption in the defective sites of NS-ZnO.


RSC Advances ◽  
2018 ◽  
Vol 8 (65) ◽  
pp. 37021-37027 ◽  
Author(s):  
Sungjoo Kim ◽  
Chul Jong Yoo ◽  
Jae Yong Park ◽  
Sangwon Baek ◽  
Won Seok Cho ◽  
...  

Refractive-index (RI)-matched nanostructures are implemented in GaN-based light-emitting diodes (LEDs) for enhancing light output efficiency.


2010 ◽  
Vol 19 (4) ◽  
pp. 047205 ◽  
Author(s):  
Huang Jun-Yi ◽  
Fan Guang-Han ◽  
Zheng Shu-Wen ◽  
Niu Qiao-Li ◽  
Li Shu-Ti ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Huamao Huang ◽  
Haiying Hu ◽  
Hong Wang ◽  
Kuiwei Geng

The light output of dipole source in three types of light-emitting diodes (LEDs), including the conventional planar LED, the nanorod LED, and the localized surface plasmon (LSP) assisted LED by inserting silver nanoparticles in the gaps between nanorods, was studied by use of two-dimensional finite difference time domain method. The height of nanorod and the size of silver nanoparticles were variables for discussion. Simulation results show that a large height of nanorod induces strong wavelength selectivity, which can be significantly enhanced by LSP. On condition that the height of nanorod is 400 nm, the diameter of silver nanoparticle is 100 nm, and the wavelength is 402.7 nm, the light-output efficiency for LSP assisted LED is enhanced by 190% or 541% as compared to the nanorod counterpart or the planar counterpart, respectively. The space distribution of Poynting vector was present to demonstrate the significant enhancement of light output at the resonant wavelength of LSP.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Sang Hyun Jung ◽  
Keun Man Song ◽  
Young Su Choi ◽  
Hyeong-Ho Park ◽  
Hyun-Beom Shin ◽  
...  

Various nanopatterns on the transparent conducting indium tin oxide (ITO) layer are investigated to enhance the light extraction efficiency of the InGaN/GaN light-emitting diodes (LEDs). Triangular, square, and circular nanohole patterns with the square and hexagonal lattices are fabricated on the ITO layer by an electron beam lithography and inductively coupled plasma dry etching processes. The circular hole pattern with a hexagonal geometry is found to be the most effective among the studied structures. Light output intensity measurements reveal that the circular hole nanopatterned ITO LEDs with a hexagonal lattice show up to 35.6% enhancement of output intensity compared to the sample without nanopatterns.


2015 ◽  
Vol 139 ◽  
pp. 39-42 ◽  
Author(s):  
Yibin Yang ◽  
Yuan Ren ◽  
Yangxiang Chen ◽  
Minggang Liu ◽  
Weijie Chen ◽  
...  

2011 ◽  
Vol 19 (23) ◽  
pp. 23111 ◽  
Author(s):  
Tae Hoon Seo ◽  
Kang Jea Lee ◽  
Ah Hyun Park ◽  
Chang-Hee Hong ◽  
Eun-Kyung Suh ◽  
...  

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