scholarly journals SILAR-Based Application of Various Nanopillars on GaN-Based LED to Enhance Light-Extraction Efficiency

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. C. Shei
Keyword(s):  
Output Power ◽  
Indium Tin Oxide ◽  
Extraction Efficiency ◽  
Light Output ◽  
Contact Layer ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Operating Voltage ◽  
Light Output Power ◽  
The Difference

We reported the various nanopillars on GaN-based LED to enhance light-extraction efficiency prepared by successive ionic layer adsorption and reaction method (SILAR). Indium tin oxide (ITO) with thickness of 1 μm as transparent contact layer was grown to improve the electrical characteristics of the LEDs, including series resistance and operating voltage. SILAR-deposition ZnO nanoparticles on SiO2were used as etching nanomasks. Multiple nanopillars were simultaneously formed on overall surfaces of ITO p- and n-GaN by ICP etching. The proposed GaN-based LEDs with nanopillars increase light output power by 7%–20.3% (at 20 mA) over that of regular GaN-based LEDs. The difference in light output power can be attributed to differences in materials and shapes of nanopillars, resulting in a reduction in Fresnel reflection by the roughened surface of GaN-based LEDs.

scholarly journals Enhanced Light Extraction of Flip-Chip Mini-LEDs with Prism-Structured Sidewall

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 319 ◽  
Author(s):  
Bin Tang ◽  
Jia Miao ◽  
Yingce Liu ◽  
Hui Wan ◽  
Ning Li ◽  
...  
Keyword(s):  
Total Internal Reflection ◽  
Flip Chip ◽  
Extraction Efficiency ◽  
Light Output ◽  
Cost Effective ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Light Output Power ◽  
Light Emitting ◽  
Air Interface

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.

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
Keyword(s):  
Output Power ◽  
Light Output ◽  
Light Extraction Efficiency ◽  
Fresnel Reflection ◽  
Light Output Power ◽  
Light Emitting ◽  
Icp Etching ◽  
Layer Adsorption ◽  
Roughened Surface ◽  
Etching Mask

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.

scholarly journals GEOMETRICAL ANALYSIS OF LIGHT-EMITTING DIODE FOR ENHANCING EXTRACTION EFFICIENCY

2020 ◽  
Vol 15 (6) ◽  
pp. 68-84
Author(s):  
ADAM SHAARI ◽  
◽  
AHMAD FAKHRURRAZI AHMAD NOORDEN ◽  
SAIFUL NAJMEE MOHAMAD ◽  
SUZAIRI DAUD ◽  
...  
Keyword(s):  
Contact Area ◽  
Indium Tin Oxide ◽  
Extraction Efficiency ◽  
Light Emitting Diode ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Current Spreading ◽  
Light Emitting ◽  
Uniform Current ◽  
Electrode Contact

A non-uniform current spreading in the current spreader can greatly reduce the efficiency of the light-emitting diode (LED). The effects of the electrode contact area to the spreading layer towards extraction efficiency of LED chips is analysed in analytical simulations. Length of current spreading and light extraction efficiency is analysed for variation of contact area. The contact area value is varied by changing the shape of the electrode and the value of width of contact area. The increase in contact area decreases light extraction efficiency as more light are absorbed by the bottom electrode surface. The effective current spreading length for Indium Tin Oxide (ITO) of thickness 300nm is 36.44µm. The 6 strips ‘fork’ design is the most optimum. The design has the most area for photons produced in active region to escape without reducing the area cover with current density. This enables the chip to has more extraction efficiency with more uniform current spreading.

Hybrid indium tin oxide/Ag nanowire electrodes for improving the light output power of near ultraviolet AlGaN-based light-emitting diode

2016 ◽  
Vol 16 (5) ◽  
pp. 545-548 ◽  
Author(s):  
Jae-Seong Park ◽  
Jae-Ho Kim ◽  
Jun-Yong Kim ◽  
Dae-Hyun Kim ◽  
Daesung Kang ◽  
...  
Keyword(s):  
Output Power ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Light Emitting Diode ◽  
Light Output ◽  
Light Output Power ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Ag Nanowire

scholarly journals Enhanced light output power of near UV light emitting diodes with graphene / indium tin oxide nanodot nodes for transparent and current spreading electrode

2011 ◽  
Vol 19 (23) ◽  
pp. 23111 ◽  
Author(s):  
Tae Hoon Seo ◽  
Kang Jea Lee ◽  
Ah Hyun Park ◽  
Chang-Hee Hong ◽  
Eun-Kyung Suh ◽  
...  
Keyword(s):  
Output Power ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Uv Light ◽  
Light Output ◽  
Light Output Power ◽  
Current Spreading ◽  
Light Emitting
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