Intrinsic excitation-dependent room-temperature internal quantum efficiency of AlGaN nanowires with varying Al contents

2021 ◽  
Vol 39 (2) ◽  
pp. 022803
Author(s):  
Jiaying Lu ◽  
Yun Zhong ◽  
Songrui Zhao
Keyword(s):  
Quantum Efficiency ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Intrinsic Excitation

scholarly journals AlGaN Nanostructures with Extremely High Room-Temperature Internal Quantum Efficiency of Emission Below 300 nm

2016 ◽  
Vol 46 (7) ◽  
pp. 3888-3893 ◽  
Author(s):  
A. A. Toropov ◽  
E. A. Shevchenko ◽  
T. V. Shubina ◽  
V. N. Jmerik ◽  
D. V. Nechaev ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Room Temperature ◽  
Internal Quantum Efficiency

scholarly journals Measuring the internal quantum efficiency of light-emitting diodes: towards accurate and reliable room-temperature characterization

Nanophotonics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 1601-1615 ◽  
Author(s):  
Jong-In Shim ◽  
Dong-Soo Shin
Keyword(s):  
Quantum Efficiency ◽  
Room Temperature ◽  
Light Emitting Diodes ◽  
Internal Quantum Efficiency ◽  
Measurement Techniques ◽  
Physical Parameters ◽  
Temperature Dependent ◽  
Reliable Measurement ◽  
Light Emitting ◽  
Temperature Reference

AbstractFor accurate and reliable measurement of the internal quantum efficiency (IQE) of light-emitting diodes (LEDs), the method should be theoretically solid and experimentally simple to use without any prior assumption of physical parameters or complicated equipment. In this paper, we critically review the conventional characterization techniques for measuring the IQE of LEDs, including the methods based on temperature-dependent electroluminescence and constant AB(C) models. After reviewing the limitations of the existing IQE measurement techniques, we present the recently proposed method based on the improved AB model, called room-temperature reference-point method (RTRM). The RTRM is then applied to various LED devices to show how the IQE measurement techniques can be utilized to analyze their optoelectronic performances quantitatively.

Efficient Luminescence from {11.2} InGaN/GaN Quantum Wells

2004 ◽  
Vol 831 ◽  
Author(s):  
Mitsuru Funato ◽  
Koji Nishizuka ◽  
Yoichi Kawakami ◽  
Yukio Narukawa ◽  
Takashi Mukai
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Radiative Recombination ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Multiple Quantum ◽  
Photoluminescence Intensity ◽  
Growth Technique ◽  
Recombination Lifetime ◽  
Piezoelectric Fields

ABSTRACTInGaN/GaN multiple quantum wells (MQWs) with [0001], <11.2>, and <11.0> orientations have been fabricated by means of the re-growth technique on patterned GaN templates with striped geometry, normal planes of which are (0001) and {11.0}, on sapphire (0001) substrates. It was found that photoluminescence intensity of the {11.2} QW is the strongest among the three QWs, and its internal quantum efficiency was estimated to be as large as about 40% at room temperature. The radiative recombination lifetime of the {11.2} QW was about 0.39 ns at 14 K, which was 3.8 times shorter than that of conventional c-oriented QWs emitting at a similar wavelength. These findings are well explained by the high internal quantum efficiency in the {11.2} QW owing to the suppression of piezoelectric fields.

scholarly journals Effects of a Si-doped InGaN Underlayer on the Optical Properties of InGaN/GaN Quantum Well Structures with Different Numbers of Quantum Wells

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1736 ◽  
Author(s):  
George Christian ◽  
Menno Kappers ◽  
Fabien Massabuau ◽  
Colin Humphreys ◽  
Rachel Oliver ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Wells ◽  
Quantum Efficiency ◽  
Radiative Recombination ◽  
Room Temperature ◽  
Internal Quantum Efficiency ◽  
Thermionic Emission ◽  
Radiative Recombination Rate ◽  
Quantum Well Structures ◽  
Si Doped

In this paper we report on the optical properties of a series of InGaN polar quantum well structures where the number of wells was 1, 3, 5, 7, 10 and 15 and which were grown with the inclusion of an InGaN Si-doped underlayer. When the number of quantum wells is low then the room temperature internal quantum efficiency can be dominated by thermionic emission from the wells. This can occur because the radiative recombination rate in InGaN polar quantum wells can be low due to the built-in electric field across the quantum well which allows the thermionic emission process to compete effectively at room temperature limiting the internal quantum efficiency. In the structures that we discuss here, the radiative recombination rate is increased due to the effects of the Si-doped underlayer which reduces the electric field across the quantum wells. This results in the effect of thermionic emission being largely eliminated to such an extent that the internal quantum efficiency at room temperature is independent of the number of quantum wells.

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.

The novel Sr3LiSbO6:Mn4+, Ca2+ far-red-emitting phosphors with over 95% internal quantum efficiency for indoor plant growth LEDs

2021 ◽  
Vol 237 ◽  
pp. 118165
Author(s):  
Linyan Fu ◽  
Yunlong Yang ◽  
Yi Zhang ◽  
Xuefei Ren ◽  
Yingjie Zhu ◽  
...  
Keyword(s):  
Plant Growth ◽  
Quantum Efficiency ◽  
Internal Quantum Efficiency ◽  
The Novel

Pure room temperature phosphorescence emission of organic host-guest doped system with quantum efficiency of 64%

2021 ◽  
Author(s):  
Xiaoqing Liu ◽  
Wenbo Dai ◽  
Qian Junjie ◽  
Yunxiang Lei ◽  
Miaochang Liu ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Room Temperature ◽  
Room Temperature Phosphorescence ◽  
Halogen Atoms ◽  
System P ◽  
Phosphorescence Emission

A new doped system with pure phosphorescent emission is constructed using four 1-(4-(diphenylamino)phenyl)-2-phenylethan-1-one derivatives containing halogen atoms as the guests and benzophenone as the host. That is, the doped system...

Perovskite Light‐Emitting Diodes with Near Unit Internal Quantum Efficiency at Low Temperatures

2021 ◽  
Vol 33 (14) ◽  
pp. 2006302
Author(s):  
Yarong He ◽  
Jiaxu Yan ◽  
Lei Xu ◽  
Bangmin Zhang ◽  
Qian Cheng ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Low Temperatures ◽  
Light Emitting Diodes ◽  
Internal Quantum Efficiency ◽  
Light Emitting
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