Photocurrent spectroscopy as a tool for determining piezoelectric fields inInxGa1−xN/GaNmultiple quantum well light emitting diodes

2004 ◽  
Vol 69 (4) ◽  
Author(s):  
G. Franssen ◽  
P. Perlin ◽  
T. Suski
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Photocurrent Spectroscopy ◽  
Piezoelectric Fields

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.

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

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.

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

Improvement of efficiency droop in InGaN/GaN multiple quantum well light-emitting diodes with trapezoidal wells

2010 ◽  
Vol 43 (35) ◽  
pp. 354004 ◽  
Author(s):  
Sang-Heon Han ◽  
Dong-Yul Lee ◽  
Hyun-Wook Shim ◽  
Gwon-Chul Kim ◽  
Young Sun Kim ◽  
...  
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Multiple Quantum Well ◽  
Efficiency Droop ◽  
Multiple Quantum ◽  
Light Emitting

Improvement of the Efficiency of InGaN–GaN Quantum-Well Light-Emitting Diodes Grown With a Pulsed-Trimethylindium Flow Process

2009 ◽  
Vol 21 (7) ◽  
pp. 414-416 ◽  
Author(s):  
Tao-Hung Hsueh ◽  
Jinn-Kong Sheu ◽  
Wei-Chi Lai ◽  
Yi-Ting Wang ◽  
Hao-Chung Kuo ◽  
...  
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Flow Process ◽  
Light Emitting
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