Round Holes Pattern Design on Patterned Sapphire Substrate of GaN-Based LEDs

2013 ◽  
Vol 321-324 ◽  
pp. 474-477
Author(s):  
Xin Yu Yu ◽  
Jun Zhang ◽  
Zhe Chen ◽  
Meng Yuan Xie ◽  
Jian Hui Yu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Sapphire Substrate ◽  
External Quantum Efficiency ◽  
Light Emitting Diode ◽  
Maximum Enhancement ◽  
Pattern Design ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Simulation Results

Patterned sapphire substrate (PSS) is effective approach to improve external quantum efficiency of light emitting diode (LED) chip. The round holes pattern was studied in this paper. Simulation was used to study how external quantum efficiency changes in different parameters of the round holes for flip GaN-based LEDs fabricated round holes PSS. Through a series of comparisons on simulation results, the maximum enhancement of LED’s external quantum efficiency is 15% compared to the external quantum efficiency of non-patterned sapphire substrate (non-PSS) LED for a most effective pattern.

Enhancement of the External Quantum Efficiency of a Silicon Quantum Dot Light-Emitting Diode by Localized Surface Plasmons

2008 ◽  
Vol 20 (16) ◽  
pp. 3100-3104 ◽  
Author(s):  
Beak-Hyun Kim ◽  
Chang-Hee Cho ◽  
Jin-Soo Mun ◽  
Min-Ki Kwon ◽  
Tae-Young Park ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Surface Plasmons ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diode ◽  
Localized Surface Plasmons ◽  
Light Emitting ◽  
Silicon Quantum Dot

N-face GaN substrate roughening for improved performance GaN-on-GaN LED

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ezzah Azimah Alias ◽  
Muhammad Esmed Alif Samsudin ◽  
Steven DenBaars ◽  
James Speck ◽  
Shuji Nakamura ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diode ◽  
Optical Power ◽  
Ammonium Hydroxide ◽  
Content Type ◽  
Light Emitting ◽  
Gan Led ◽  
Improved Performance ◽  
Substrate Roughening

Purpose This study aims to focus on roughening N-face (backside) GaN substrate prior to GaN-on-GaN light-emitting diode (LED) growth as an attempt to improve the LED performance. Design/methodology/approach The N-face of GaN substrate was roughened by three different etchants; ammonium hydroxide (NH4OH), a mixture of NH4OH and H2O2 (NH4OH: H2O2) and potassium hydroxide (KOH). Hexagonal pyramids were successfully formed on the surface when the substrate was subjected to the etching in all cases. Findings Under 30 min of etching, the highest density of pyramids was obtained by NH4OH: H2O2 etching, which was 5 × 109 cm–2. The density by KOH and NH4OH etchings was 3.6 × 109 and 5 × 108 cm–2, respectively. At standard operation of current density at 20 A/cm2, the optical power and external quantum efficiency of the LED on the roughened GaN substrate by NH4OH: H2O2 were 12.3 mW and 22%, respectively, which are higher than its counterparts. Originality/value This study demonstrated NH4OH: H2O2 is a new etchant for roughening the N-face GaN substrate. The results showed that such etchant increased the density of the pyramids on the N-face GaN substrate, which subsequently resulted in higher optical power and external quantum efficiency to the LED as compared to KOH and NH4OH.

Improved Light Extraction Efficiency of Light-Emitting Diode Grown on Nanoscale-Silicon-Dioxide-Patterned Sapphire Substrate

2020 ◽  
Vol 12 (5) ◽  
pp. 647-651 ◽  
Author(s):  
Young Hoon Sung ◽  
Jaemin Park ◽  
Eun-Seo Choi ◽  
Hee Chul Lee ◽  
Heon Lee
Keyword(s):  
Silicon Dioxide ◽  
Sapphire Substrate ◽  
Extraction Efficiency ◽  
Light Emitting Diode ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Patterned Sapphire Substrate ◽  
Light Emitting ◽  
Sapphire Wafer ◽  
Luminescence Efficiency

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.

Sign in / Sign up

Export Citation Format

Share Document