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.

Measurement of the internal quantum efficiency of InGaN quantum wells

2007 ◽  
Author(s):  
A. Laubsch ◽  
M. Sabathil ◽  
G. Bruederl ◽  
J. Wagner ◽  
M. Strassburg ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Internal Quantum Efficiency ◽  
Ingan Quantum Wells

scholarly journals High Temperature and Power Dependent Photoluminescence Analysis on Commercial Lighting and Display LED Materials for Future Power Electronic Modules

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Abbas Sabbar ◽  
Syam Madhusoodhanan ◽  
Sattar Al-Kabi ◽  
Binzhong Dong ◽  
Jiangbo Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Quantum Wells ◽  
Quantum Efficiency ◽  
Spontaneous Emission ◽  
Light Emitting Diode ◽  
Internal Quantum Efficiency ◽  
Multiple Quantum ◽  
Power Electronic ◽  
Light Emitting ◽  
Red Led

AbstractCommercial light emitting diode (LED) materials - blue (i.e., InGaN/GaN multiple quantum wells (MQWs) for display and lighting), green (i.e., InGaN/GaN MQWs for display), and red (i.e., Al0.05Ga0.45In0.5P/Al0.4Ga0.1In0.5P for display) are evaluated in range of temperature (77–800) K for future applications in high density power electronic modules. The spontaneous emission quantum efficiency (QE) of blue, green, and red LED materials with different wavelengths was calculated using photoluminescence (PL) spectroscopy. The spontaneous emission QE was obtained based on a known model so-called the ABC model. This model has been recently used extensively to calculate the internal quantum efficiency and its droop in the III-nitride LED. At 800 K, the spontaneous emission quantum efficiencies are around 40% for blue for lighting and blue for display LED materials, and it is about 44.5% for green for display LED materials. The spontaneous emission QE is approximately 30% for red for display LED material at 800 K. The advance reported in this paper evidences the possibility of improving high temperature optocouplers with an operating temperature of 500 K and above.

Optical polarization and internal quantum efficiency for InGaN quantum wells on a-plane GaN

2010 ◽  
Vol 405 (7) ◽  
pp. 1857-1860 ◽  
Author(s):  
E.Y. Lin ◽  
C.Y. Chen ◽  
T.S. Lay ◽  
Z.X. Peng ◽  
T.Y. Lin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Internal Quantum Efficiency ◽  
Optical Polarization ◽  
Ingan Quantum Wells

scholarly journals High internal quantum efficiency of long wavelength InGaN quantum wells

2021 ◽  
Vol 119 (7) ◽  
pp. 071102
Author(s):  
Saulius Marcinkevičius ◽  
Rinat Yapparov ◽  
Yi Chao Chow ◽  
Cheyenne Lynsky ◽  
Shuji Nakamura ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Efficiency ◽  
Internal Quantum Efficiency ◽  
Long Wavelength ◽  
Ingan 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.

scholarly journals Spatio-Time-Resolved Cathodoluminescence Spectroscopy Imaging: Microscopic Recombination Kinetics in Semi-Polar InGaN Quantum Wells

2010 ◽  
Vol 16 (S2) ◽  
pp. 812-813
Author(s):  
J Christen ◽  
F Bertram ◽  
S Metzner ◽  
T Wunderer ◽  
F Lipski ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Time Resolved ◽  
Cathodoluminescence Spectroscopy ◽  
Recombination Kinetics ◽  
Ingan Quantum Wells

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Low-temperature internal quantum efficiency of GaInN/GaN quantum wells under steady-state conditions

2022 ◽  
Author(s):  
Shawutijiang Sidikejiang ◽  
Philipp Henning ◽  
Philipp Horenburg ◽  
Heiko Bremers ◽  
Uwe Rossow ◽  
...  
Keyword(s):  
Low Temperature ◽  
Quantum Wells ◽  
Internal Quantum Efficiency ◽  
Structural Defects ◽  
Measured Intensity ◽  
Time Resolved ◽  
Absorbed Power ◽  
Radiative Losses ◽  
Effects Of Temperature ◽  
Excitation Conditions

Abstract We compare the low-temperature photoluminescence (PL) intensities of a range of GaInN/GaN quantum well (QW) structures under identical excitation conditions, mounting the samples side by side. Normalizing the measured intensity to the absorbed power density in the QWs, we find that low-temperature PL efficiencies of several samples, which show close to 100% IQE in time-resolved PL, saturate at nearly an identical value. Of course, this is strong indicative of being 100% IQE at low temperature for those efficient samples. Using the low-temperature PL efficiency as a ``Reference'', on the other hand, we observe not only the effects of temperature-independent non-radiative losses on the low-temperature IQE, but also are able to determine the IQE of arbitrary samples on an absolute scale. Furthermore, we prove the experimental results by comparing the low-temperature efficiencies of a sample with an initial 100% IQE after intentionally introducing structural defects with argon-implantation.

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