A Numerical Study of Influence of Photonic Crystals on the Light Extraction Efficiency and Far Field Radiation Characteristics of Light-Emitting Diode

2010 ◽  
Vol 39 (8) ◽  
pp. 1500-1504
Author(s):  
王靖 WANG Jing ◽  
吴立军 WU Li-jun
Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 767 ◽  
Author(s):  
Hong Wang ◽  
Ming Zhong ◽  
Lijun Tan ◽  
Wei Shi ◽  
Quanbin Zhou

In this study, the photonic crystal structure is employed to increase both the light extraction efficiency and the modulation bandwidth of flip-chip GaN-based light-emitting diodes (LEDs). The finite difference time domain method is utilized to investigate the influence of structure of photonic crystals on the Purcell factor and light extraction efficiency of flip-chip GaN-based LEDs. Simulation results show that the modulation bandwidth is estimated to be 202 MHz at current densities of 1000 A/cm2. The experimental result of modulation bandwidth is in accord with the simulation. The optical f-3dB of the device achieves 212 MHz at current densities of 1000 A/cm2 and up to 285 MHz at current densities of 2000 A/cm2. This design of photonic crystal flip-chip LED has the potential for applications in high-frequency visible light communication.


2020 ◽  
Vol 12 (5) ◽  
pp. 647-651 ◽  
Author(s):  
Young Hoon Sung ◽  
Jaemin Park ◽  
Eun-Seo Choi ◽  
Hee Chul Lee ◽  
Heon Lee

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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