scholarly journals Sensitivity Analysis of GaN/AlGaN Quantum Dot Based Led

2021 ◽  
Author(s):  
Sumathi Kandasamy ◽  
Nagarajan K K ◽  
Srinivasan R
Keyword(s):  
Quantum Dot ◽  
Quantum Efficiency ◽  
Performance Metrics ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Optical Gain ◽  
Input Power ◽  
Geometrical Parameters ◽  
Significant Parameter ◽  
The Impact

Abstract The impact of various geometrical parameters and doping parameters on the performance of GaN/AlGaN quantum dot-based light-emitting diode using 3D numerical simulations have been studied in this work. The parameters are ranked based on their sensitivity coefficients. Four important performance metrics, (i) internal quantum efficiency, (ii) responsivity, (iii) optical gain, and (iv) input power are used for this study. The bottom radius of the quantum dot is found to be the most significant parameter with respect to the internal quantum efficiency and optical gain. Nanocolumn radius is the most significant parameter with respect to Responsivity and input power. The overall ranking suggests that the Nanocolumn radius is the most sensitive parameter.

scholarly journals Perspectives on UVC LED: Its Progress and Application

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 196
Author(s):  
Tsung-Chi Hsu ◽  
Yu-Tsai Teng ◽  
Yen-Wei Yeh ◽  
Xiaotong Fan ◽  
Kuo-Hsiung Chu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Flip Chip ◽  
Layer Structure ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Reverse Current ◽  
Light Extraction ◽  
Epitaxial Layers ◽  
High Electron ◽  
Recombination Rates

High-quality epitaxial layers are directly related to internal quantum efficiency. The methods used to design such epitaxial layers are reviewed in this article. The ultraviolet C (UVC) light-emitting diode (LED) epitaxial layer structure exhibits electron leakage; therefore, many research groups have proposed the design of blocking layers and carrier transportation to generate high electron–hole recombination rates. This also aids in increasing the internal quantum efficiency. The cap layer, p-GaN, exhibits high absorption in deep UV radiation; thus, a small thickness is usually chosen. Flip chip design is more popular for such devices in the UV band, and the main factors for consideration are light extraction and heat transportation. However, the choice of encapsulation materials is important, because unsuitable encapsulation materials will be degraded by ultraviolet light irradiation. A suitable package design can account for light extraction and heat transportation. Finally, an atomic layer deposition Al2O3 film has been proposed as a mesa passivation layer. It can provide a low reverse current leakage. Moreover, it can help increase the quantum efficiency, enhance the moisture resistance, and improve reliability. UVC LED applications can be used in sterilization, water purification, air purification, and medical and military fields.

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

scholarly journals Enhancement of quantum efficiency in InGaN quantum wells by using superlattice interlayers and pulsed growth

2016 ◽  
Vol 55 (4) ◽  
Author(s):  
Kazimieras Nomeika ◽  
Mantas Dmukauskas ◽  
Ramūnas Aleksiejūnas ◽  
Patrik Ščajev ◽  
Saulius Miasojedovas ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Recombination Coefficient ◽  
Time Resolved ◽  
Mocvd Growth ◽  
Lower Strain ◽  
Type Contact ◽  
Ingan Quantum Wells

Enhancement of internal quantum efficiency (IQE) in InGaN quantum wells by insertion of a superlattice interlayer and applying the pulsed growth regime is investigated by a set of time-resolved optical techniques. A threefold IQE increase was achieved in the structure with the superlattice. It was ascribed to the net effect of decreased internal electrical field due to lower strain and altered carrier localization conditions. Pulsed MOCVD growth also resulted in twice higher IQE, presumably due to better control of defects in the structure. An LED (light emitting diode) structure with a top p-type contact GaN layer was manufactured by using both growth techniques with the peak IQE equal to that in the underlying quantum well structure. The linear recombination coefficient was found to gradually increase with excitation due to carrier delocalization, and the latter dependence was successfully used to fit the IQE droop.

scholarly journals Static Characterization of the Birefringence Effect in the Semiconductor Optical Amplifier Using the Finite Difference Method

2015 ◽  
Vol 5 (1) ◽  
pp. 38
Author(s):  
A. Elyamani ◽  
A. Zatni ◽  
H. Bousseta ◽  
A. Moumen
Keyword(s):  
Numerical Model ◽  
Semiconductor Optical Amplifier ◽  
Optical Power ◽  
Optical Amplifier ◽  
Input Power ◽  
Geometrical Parameters ◽  
Saturated Gain ◽  
Birefringence Effect ◽  
The Impact

Knowing the various physical mechanisms of the semiconductor optical amplifier (SOA) helps us to develop a more complete numerical model. It also enables us to simulate more realistically the static behavior of the SOA<sub>s</sub>’ birefringence effect. This way, it allows us to study more precisely the behavior of SOA<sub>s</sub>, and particularly the impact of the amplified spontaneous emission (ASE) or the pump and probe signals as well as the optical functions based on the non-linearity of the component. In static regime, the SOA<sub>s</sub> possess a very low amplification threshold and a saturation power of the gain which mainly depends on the optical power injected into the active region. Beyond the optical input power, the SOA is in the saturated gain regime which gives it a nonlinear transmission behavior. Our detailed numerical model offers a set of equations and an algorithm that predict their behavior. The equations form a theoretical base from which we have coded our model in several files.cpp that the <strong>Language C++</strong> executes. It has enabled us, from the physical and geometrical parameters of the component, to recover all the relevant values ​​for a comprehensive study of SOA<sub>s</sub> in static and dynamic regimes. In this paper, we propose to make a static characterization of the effect of the nonlinear polarization rotation by realizing a pump-probe assemblage to control the power and state of polarization at the entering of the SOA.

scholarly journals Internal quantum efficiency of AlGaN/AlN quantum dot superlattices for electron-pumped ultraviolet sources

2020 ◽  
Vol 31 (50) ◽  
pp. 505205
Author(s):  
A Harikumar ◽  
F Donatini ◽  
C Bougerol ◽  
E Bellet-Amalric ◽  
Q -M Thai ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Quantum Efficiency ◽  
Internal Quantum Efficiency

scholarly journals Internal quantum efficiency improvement of InGaN/GaN multiple quantum well green light-emitting diodes

2016 ◽  
Vol 24 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Q. Zhou ◽  
M. Xu ◽  
H. Wang
Keyword(s):  
Quantum Well ◽  
Quantum Efficiency ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Multiple Quantum Well ◽  
Visible Light Communication ◽  
Multiple Quantum ◽  
Internal Electric Field ◽  
Light Emitting ◽  
Green Led

In recent years, GaN-based light-emitting diode (LED) has been widely used in various applications, such as RGB lighting system, full-colour display and visible-light communication. However, the internal quantum efficiency (IQE) of green LEDs is significantly lower than that of other visible spectrum LED. This phenomenon is called “green gap”. This paper briefly describes the physical mechanism of the low IQE for InGaN/GaN multiple quantum well (MQW) green LED at first. The IQE of green LED is limited by the defects and the internal electric field in MQW. Subsequently, we discuss the recent progress in improving the IQE of green LED in detail. These strategies can be divided into two categories. Some of these methods were proposed to enhance crystal quality of InGaN/GaN MQW with high In composition and low density of defects by modifying the growth conditions. Other methods focused on increasing electron-hole wave function overlap by eliminating the polarization effect.

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