Improved light-output power of InGaN-based multiple-quantum-well light-emitting diodes by GaN/InAlGaN/GaN multi-barrier

2016 ◽  
Vol 16 (2) ◽  
pp. 150-154 ◽  
Author(s):  
Jongmin Kim ◽  
Bong Kyun Kang ◽  
Sung-Nam Lee ◽  
Jehyuk Choi ◽  
Keun Man Song
Keyword(s):  
Quantum Well ◽  
Output Power ◽  
Light Emitting Diodes ◽  
Multiple Quantum Well ◽  
Light Output ◽  
Multiple Quantum ◽  
Light Output Power ◽  
Light Emitting

Low-Temperature Operation of Green, Blue and UV InGaN/GaN Multiple-Quantum-Well Light-Emitting Diodes

2003 ◽  
Vol 764 ◽  
Author(s):  
X. A. Cao ◽  
S. F. LeBoeuf ◽  
J. L. Garrett ◽  
A. Ebong ◽  
L. B. Rowland ◽  
...  
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Multiple Quantum Well ◽  
Light Output ◽  
Localized States ◽  
Multiple Quantum ◽  
Nonradiative Recombination ◽  
Light Emitting ◽  
Temperature Range ◽  
Green Leds

Absract:Temperature-dependent electroluminescence (EL) of InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs) with peak emission energies ranging from 2.3 eV (green) to 3.3 eV (UV) has been studied over a wide temperature range (5-300 K). As the temperature is decreased from 300 K to 150 K, the EL intensity increases in all devices due to reduced nonradiative recombination and improved carrier confinement. However, LED operation at lower temperatures (150-5 K) is a strong function of In ratio in the active layer. For the green LEDs, emission intensity increases monotonically in the whole temperature range, while for the blue and UV LEDs, a remarkable decrease of the light output was observed, accompanied by a large redshift of the peak energy. The discrepancy can be attributed to various amounts of localization states caused by In composition fluctuation in the QW active regions. Based on a rate equation analysis, we find that the densities of the localized states in the green LEDs are more than two orders of magnitude higher than that in the UV LED. The large number of localized states in the green LEDs are crucial to maintain high-efficiency carrier capture at low temperatures.

Enhancement of the Optical Output Power of InGaN/GaN Multiple Quantum Well Light-Emitting Diodes by a CoFe Ferromagnetic Layer

ACS Photonics ◽  
2015 ◽  
Vol 2 (11) ◽  
pp. 1519-1523 ◽  
Author(s):  
Jae-Joon Kim ◽  
Young-Chul Leem ◽  
Jang-Won Kang ◽  
Joonhyun Kwon ◽  
Beongki Cho ◽  
...  
Keyword(s):  
Quantum Well ◽  
Output Power ◽  
Light Emitting Diodes ◽  
Multiple Quantum Well ◽  
Ferromagnetic Layer ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Optical Output Power ◽  
Optical Output

Realization of Broad-Spectrum Using Chirped Multi-Quantum Well Structures in AlGaInP-Based Light-Emitting Diodes

2021 ◽  
Vol 21 (7) ◽  
pp. 3824-3828
Author(s):  
Hwa Sub Oh ◽  
Jong-Min Park ◽  
Seong Hoon Jeong ◽  
Jun-Beom Park ◽  
Tak Jeong ◽  
...  
Keyword(s):  
Quantum Well ◽  
Output Power ◽  
Broad Spectrum ◽  
Light Emitting Diodes ◽  
Light Output ◽  
Light Output Power ◽  
Light Emitting ◽  
Quantum Well Structures ◽  
Optical Output ◽  
Multi Quantum Well

We studied broad-spectrum light emitting diodes appropriate for special lighting applications in terms of their optical behaviors and device performances according to the chirped multi-quantum well structures. As the well thickness from 1 st to 3rd well was changed from 6 nm to 15 nm and repeated three times, the electroluminescent spectrum was broadened by 65% and the light output power was increased by 8% in comparison to light emitting diodes having conventional multi-quantum well structures. In the case of the chirped multi-quantum well structures having sequentially decreasing the well thickness from 15 nm to 6 nm and repeating three times, the optical output power was decreased by 5% due to the carrier leakage out of the active region.

scholarly journals Improved Performance of GaN-Based Light-Emitting Diodes Grown on Si (111) Substrates with NH3 Growth Interruption

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 399
Author(s):  
Sang-Jo Kim ◽  
Semi Oh ◽  
Kwang-Jae Lee ◽  
Sohyeon Kim ◽  
Kyoung-Kook Kim
Keyword(s):  
Buffer Layer ◽  
Light Emitting Diodes ◽  
Defect Density ◽  
Strain Relaxation ◽  
Multiple Quantum Well ◽  
Light Output ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Growth Interruption ◽  
Aln Buffer

We demonstrate the highly efficient, GaN-based, multiple-quantum-well light-emitting diodes (LEDs) grown on Si (111) substrates embedded with the AlN buffer layer using NH3 growth interruption. Analysis of the materials by the X-ray diffraction omega scan and transmission electron microscopy revealed a remarkable improvement in the crystalline quality of the GaN layer with the AlN buffer layer using NH3 growth interruption. This improvement originated from the decreased dislocation densities and coalescence-related defects of the GaN layer that arose from the increased Al migration time. The photoluminescence peak positions and Raman spectra indicate that the internal tensile strain of the GaN layer is effectively relaxed without generating cracks. The LEDs embedded with an AlN buffer layer using NH3 growth interruption at 300 mA exhibited 40.9% higher light output power than that of the reference LED embedded with the AlN buffer layer without NH3 growth interruption. These high performances are attributed to an increased radiative recombination rate owing to the low defect density and strain relaxation in the GaN epilayer.

High-Bright InGaN Multiple-Quantum-Well Blue Light-Emitting Diodes on Si (111) Using AlN/GaN Multilayers with a Thin AlN/AlGaN Buffer Layer

2003 ◽  
Vol 42 (Part 2, No. 3A) ◽  
pp. L226-L228 ◽  
Author(s):  
Baijun Zhang ◽  
Takashi Egawa ◽  
Hiroyasu Ishikawa ◽  
Yang Liu ◽  
Takashi Jimbo
Keyword(s):  
Quantum Well ◽  
Buffer Layer ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Algan Buffer
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