scholarly journals Light-Output Enhancement of GaN-Based Light-Emitting Diodes with Three-Dimensional Backside Reflectors Patterned by Microscale Cone Array

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Huamao Huang ◽  
Jinyong Hu ◽  
Hong Wang
Keyword(s):  
Light Emitting Diode ◽  
Three Dimensional ◽  
Light Output ◽  
Bragg Reflector ◽  
Light Extraction Efficiency ◽  
Distributed Bragg Reflector ◽  
Etching Technique ◽  
Light Emitting ◽  
Triangle Lattice ◽  
Wall Plug Efficiency

Three-dimensional (3D) backside reflector, compared with flat reflectors, can improve the probability of finding the escape cone for reflecting lights and thus enhance the light-extraction efficiency (LEE) for GaN-based light-emitting diode (LED) chips. A triangle-lattice of microscale SiO2cone array followed by a 16-pair Ti3O5/SiO2distributed Bragg reflector (16-DBR) was proposed to be attached on the backside of sapphire substrate, and the light-output enhancement was demonstrated by numerical simulation and experiments. The LED chips with flat reflectors or 3D reflectors were simulated using Monte Carlo ray tracing method. It is shown that the LEE increases as the reflectivity of backside reflector increases, and the light-output can be significantly improved by 3D reflectors compared to flat counterparts. It can also be observed that the LEE decreases as the refractive index of the cone material increases. The 3D 16-DBR patterned by microscale SiO2cone array benefits large enhancement of LEE. This microscale pattern was prepared by standard photolithography and wet-etching technique. Measurement results show that the 3D 16-DBR can provide 12.1% enhancement of wall-plug efficiency, which is consistent with the simulated value of 11.73% for the enhancement of LEE.

InGaN MQW LED structures using AlN/GaN DBR and Ag-based p-contact

2011 ◽  
Vol 1288 ◽  
Author(s):  
K. Lee ◽  
L. E. Rodak ◽  
V. Kumbham ◽  
V. Narang ◽  
J. S. Dudding ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Resonant Cavity ◽  
Light Output ◽  
Bragg Reflector ◽  
Output Intensity ◽  
Distributed Bragg Reflector ◽  
Light Emitting ◽  
Maximum Reflectivity ◽  
Average Reflectance ◽  
Multi Quantum Well

ABSTRACTResonant cavity light emitting diode (RCLED) structure was grown using digital AlGaN/GaN Distributed Bragg Reflector (DBR) and Ag-based p-contact. A five period of InGaN/GaN multi-quantum well (MQW) layers are placed between these two high reflectance mirrors. Digital AlGaN/GaN DBR have a maximum reflectivity of about 60 % at 445 nm and 90 % at 439 nm for 6 period and 12 period, respectively. Ag-based p-contact exhibits an average reflectance of around 85-90 % for a wavelength of 400-600 nm. The light output intensity of the RCLEDs with 12 period digital AlGaN/GaN DBR is higher by a factor of 3 as compared to that of the similar structure without digital AlGaN/GaN DBR at an injection current of 50 mA.

Improved Light Output of AlGaInP-Based Micro-Light Emitting Diode Using Distributed Bragg Reflector

2020 ◽  
Vol 32 (7) ◽  
pp. 438-441
Author(s):  
Sang-Youl Lee ◽  
Ji Hyung Moon ◽  
Yong-Tae Moon ◽  
Chung Song Kim ◽  
Sunwoo Park ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Light Output ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector ◽  
Light Emitting

scholarly journals Performance of GaN-Based LEDs with Nanopatterned Indium Tin Oxide Electrode

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zhanxu Chen ◽  
Wenjie Liu ◽  
Wei Wan ◽  
Gengyan Chen ◽  
Yongzhu Chen ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Ohmic Contacts ◽  
Three Dimensional ◽  
Light Output ◽  
Light Extraction Efficiency ◽  
Experimental Result ◽  
Indium Tin Oxide Electrode ◽  
Light Emitting ◽  
Ito Electrode

The indium tin oxide (ITO) has been widely applied in light emitting diodes (LEDs) as the transparent current spreading layer. In this work, the performance of GaN-based blue light LEDs with nanopatterned ITO electrode is investigated. Periodic nanopillar ITO arrays are fabricated by inductive coupled plasma etching with the mask of polystyrene nanosphere. The light extraction efficiency (LEE) of LEDs can be improved by nanopatterned ITO ohmic contacts. The light output intensity of the fabricated LEDs with nanopatterned ITO electrode is 17% higher than that of the conventional LEDs at an injection current of 100 mA. Three-dimensional finite difference time domain simulation matches well with the experimental result. This method may serve as a practical approach to improving the LEE of the LEDs.

AlGaInP Light Emitting Diode with Coupled Distributed Bragg Reflector Structure

2017 ◽  
Vol 54 (5) ◽  
pp. 052301
Author(s):  
郑元宇 Zheng Yuanyu ◽  
吴超瑜 Wu Chaoyu ◽  
林峰 Lin Feng ◽  
伍明跃 Wu Mingyue ◽  
周启伦 Zhou Qilun ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Bragg Reflector ◽  
Distributed Bragg Reflector ◽  
Light Emitting
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