BeCdSe/(Be,Zn)Se Quantum Well as a New Active Region for Blue-Green II-VI Lasers and Light-Emitting Diodes

In this study, we have proposed and investigated the effect of coupled quantum wells to reduce electron overflow in InGaN/GaN nanowire white color light-emitting diodes. The coupled quantum well before the active region could decrease the thermal velocity, which leads to a reduced electron mean free path. This improves the electron confinement in the active region and mitigates electron overflow in the devices. In addition, coupled quantum well after the active region utilizes the leaked electrons from the active region and contributes to the white light emission. Therefore, the output power and external quantum efficiency of the proposed nanowire LEDs are improved. Moreover, the efficiency droop was negligible up to 900 mA injection current.

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Effect of In incorporation into the quantum well active region on the efficiency of AlGaN-based ultraviolet light-emitting diodes

physica status solidi (c) ◽

10.1002/pssc.201100388 ◽

2012 ◽

Vol 9 (3-4) ◽

pp. 794-797 ◽

Cited By ~ 1

Author(s):

Thorsten Passow ◽

Richard Gutt ◽

Michael Kunzer ◽

Lutz Kirste ◽

Wilfried Pletschen ◽

...

Keyword(s):

Active Region ◽

Quantum Well ◽

Ultraviolet Light ◽

Light Emitting Diodes ◽

Light Emitting ◽

Ultraviolet Light Emitting Diodes

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Effects of a Reduced Effective Active Region Volume on Wavelength-Dependent Efficiency Droop of InGaN-Based Light-Emitting Diodes

Applied Sciences ◽

10.3390/app8112138 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2138 ◽

Cited By ~ 2

Author(s):

Panpan Li ◽

Yongbing Zhao ◽

Xiaoyan Yi ◽

Hongjian Li

Keyword(s):

Active Region ◽

Quantum Well ◽

Current Density ◽

Carrier Density ◽

High Efficiency ◽

Light Emitting Diodes ◽

Efficiency Droop ◽

Effective Volume ◽

Light Emitting ◽

Near Ultraviolet

In this study, wavelength-dependent efficiency droop phenomena in InGaN-based light-emitting diodes (LEDs) by a reduced effective active region volume were investigated. Different effective active region volumes can be extracted from theoretical fitting to the efficiency-versus-current curves of standard high efficiency InGaN near-ultraviolet, blue, and green LEDs. It has been found that the effective volume of the active region reduces more significantly with increasing emission wavelength, resulting in a lower onset-droop current density, as well as a more severe droop. Increasing the quantum well (QW) thickness to reduce carrier density is proposed as an effective way to alleviate the efficiency droop.

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Optimization of InGaN Based Light Emitting Diodes

Materials Science Forum ◽

10.4028/www.scientific.net/msf.517.195 ◽

2006 ◽

Vol 517 ◽

pp. 195-201

Author(s):

N. Zainal ◽

Abu Hassan Haslan ◽

Hassan Zainuriah ◽

M. Roslan Hashim ◽

Naser Mahmoud Ahmed

Keyword(s):

Active Region ◽

Quantum Well ◽

Quantum Wells ◽

Light Emitting Diodes ◽

Threshold Current ◽

Single Quantum ◽

Single Quantum Well ◽

Light Emitting ◽

Simulation Results ◽

Industrial Software

The performance of InGaN quantum well based Light Emitting Diodes; (LEDs) had been numerically investigated by using standard industrial software, Silvaco. In this work, we found that InGaN single quantum well (SQW) LEDs gives better performance than InGaN triple quantum wells LEDs. The simulation results suggest that the inhomogeneity of electron and hole distributions in quantum wells active region plays an important role in the LEDs performance. The threshold current per μm also increases as the number of quantum well is increased.

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Effect of Quantum Barrier Thickness in the Multiple-Quantum-Well Active Region of GaInN/GaN Light-Emitting Diodes

IEEE Photonics Journal ◽

10.1109/jphot.2013.2276758 ◽

2013 ◽

Vol 5 (4) ◽

pp. 1600207-1600207 ◽

Cited By ~ 13

Author(s):

Guan-Bo Lin ◽

Dong-Yeong Kim ◽

Qifeng Shan ◽

Jaehee Cho ◽

E. Fred Schubert ◽

...

Keyword(s):

Active Region ◽

Quantum Well ◽

Light Emitting Diodes ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Barrier Thickness ◽

Light Emitting

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

MRS Proceedings ◽

10.1557/proc-764-c5.5 ◽

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.

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Dimension control of in situ fabricated CsPbClBr2 nanocrystal films toward efficient blue light-emitting diodes

Nature Communications ◽

10.1038/s41467-020-20163-7 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Chenhui Wang ◽

Dengbao Han ◽

Junhui Wang ◽

Yingguo Yang ◽

Xinyue Liu ◽

...

Keyword(s):

Quantum Well ◽

Light Emitting Diodes ◽

Blue Emission ◽

Light Emitting ◽

Mixed Ligands ◽

Dimension Control ◽

Nanocrystal Films ◽

Width Distribution ◽

Quantum Well Width

AbstractIn the field of perovskite light-emitting diodes (PeLEDs), the performance of blue emissive electroluminescence devices lags behind the other counterparts due to the lack of fabrication methodology. Herein, we demonstrate the in situ fabrication of CsPbClBr2 nanocrystal films by using mixed ligands of 2-phenylethanamine bromide (PEABr) and 3,3-diphenylpropylamine bromide (DPPABr). PEABr dominates the formation of quasi-two-dimensional perovskites with small-n domains, while DPPABr induces the formation of large-n domains. Strong blue emission at 470 nm with a photoluminescence quantum yield up to 60% was obtained by mixing the two ligands due to the formation of a narrower quantum-well width distribution. Based on such films, efficient blue PeLEDs with a maximum external quantum efficiency of 8.8% were achieved at 473 nm. Furthermore, we illustrate that the use of dual-ligand with respective tendency of forming small-n and large-n domains is a versatile strategy to achieve narrow quantum-well width distribution for photoluminescence enhancement.

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