scholarly journals Optimizing the efficiency of gallium nitride‐based light‐emitting diodes from contact area of current spreading to electrode

2020 ◽  
Author(s):  
Adam Shaari ◽  
Faris Azim Ahmad Fajri ◽  
Ahmad Fakhrurrazi Ahmad Noorden ◽  
Muhammad Zamzuri Abdul Kadir ◽  
Suzairi Daud
Keyword(s):  
Gallium Nitride ◽  
Contact Area ◽  
Light Emitting Diodes ◽  
Current Spreading ◽  
Light Emitting

scholarly journals Numerical Simulation on Electrical-Thermal Properties of Gallium-Nitride-Based Light-Emitting Diodes Embedded in Board

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Xing-ming Long ◽  
Rui-jin Liao ◽  
Jing Zhou
Keyword(s):  
Finite Element ◽  
Gallium Nitride ◽  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Thermal Characteristics ◽  
Junction Temperature ◽  
Current Crowding ◽  
Total Thermal Resistance ◽  
Light Emitting ◽  
Packaging Structure

The electrical-thermal characteristics of gallium-nitride- (GaN-) based light-emitting diodes (LED), packaged by chips embedded in board (EIB) technology, were investigated using a multiphysics and multiscale finite element code, COMSOL. Three-dimensional (3D) finite element model for packaging structure has been developed and optimized with forward-voltage-based junction temperatures of a 9-chip EIB sample. The sensitivity analysis of the simulation model has been conducted to estimate the current and temperature distribution changes in EIB LED as the blue LED chip (substrate, indium tin oxide (ITO)), packaging structure (bonding wire and chip numbers), and system condition (injection current) changed. This method proved the reliability of simulated results in advance and useful material parameters. Furthermore, the method suggests that the parameter match on Shockley's equation parameters, Rs, nideal, and Is, is a potential method to reduce the current crowding effect for the EIB LED. Junction temperature decreases by approximately 3 K to 10 K can be achieved by substrate thinning, ITO, and wire bonding. The nonlinear-decreasing characteristics of total thermal resistance that decrease with an increase in chip numbers are likely to improve the thermal performance of EIB LED modules.

Device and circuit modeling of GaN/InGaN light emitting diodes (LEDs) for optimum current spreading

2003 ◽  
Vol 47 (10) ◽  
pp. 1817-1823 ◽  
Author(s):  
A. Ebong ◽  
S. Arthur ◽  
E. Downey ◽  
X.A. Cao ◽  
S. LeBoeuf ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Circuit Modeling ◽  
Current Spreading ◽  
Light Emitting

scholarly journals High-Power GaN-Based Vertical Light-Emitting Diodes on 4-Inch Silicon Substrate

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1178 ◽  
Author(s):  
Qiang Zhao ◽  
Jiahao Miao ◽  
Shengjun Zhou ◽  
Chengqun Gui ◽  
Bin Tang ◽  
...  
Keyword(s):  
High Power ◽  
Silicon Substrate ◽  
Flip Chip ◽  
Heat Dissipation ◽  
Light Emitting Diodes ◽  
Light Output ◽  
Current Spreading ◽  
Light Emitting ◽  
Fabry Perot ◽  
Lift Off

We demonstrate high-power GaN-based vertical light-emitting diodes (LEDs) (VLEDs) on a 4-inch silicon substrate and flip-chip LEDs on a sapphire substrate. The GaN-based VLEDs were transferred onto the silicon substrate by using the Au–In eutectic bonding technique in combination with the laser lift-off (LLO) process. The silicon substrate with high thermal conductivity can provide a satisfactory path for heat dissipation of VLEDs. The nitrogen polar n-GaN surface was textured by KOH solution, which not only improved light extract efficiency (LEE) but also broke down Fabry–Pérot interference in VLEDs. As a result, a near Lambertian emission pattern was obtained in a VLED. To improve current spreading, the ring-shaped n-electrode was uniformly distributed over the entire VLED. Our combined numerical and experimental results revealed that the VLED exhibited superior heat dissipation and current spreading performance over a flip-chip LED (FCLED). As a result, under 350 mA injection current, the forward voltage of the VLED was 0.36 V lower than that of the FCLED, while the light output power (LOP) of the VLED was 3.7% higher than that of the FCLED. The LOP of the FCLED saturated at 1280 mA, but the light output saturation did not appear in the VLED.

scholarly journals Improved InGaN/GaN light-emitting diodes with a p-GaN/n-GaN/p-GaN/n-GaN/p-GaN current-spreading layer

2013 ◽  
Vol 21 (4) ◽  
pp. 4958 ◽  
Author(s):  
Zi-Hui Zhang ◽  
Swee Tiam Tan ◽  
Wei Liu ◽  
Zhengang Ju ◽  
Ke Zheng ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Current Spreading ◽  
Light Emitting
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