scholarly journals Enhanced Device Performance of GaInN-Based Green Light-Emitting Diode with Sputtered AlN Buffer Layer

2019 ◽  
Vol 9 (4) ◽  
pp. 788 ◽  
Author(s):  
Seiji Ishimoto ◽  
Dong-Pyo Han ◽  
Kengo Yamamoto ◽  
Ryoya Mano ◽  
Satoshi Kamiyama ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Buffer Layer ◽  
Light Emitting Diode ◽  
Light Output ◽  
Green Light ◽  
Device Performance ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Current Characteristics ◽  
Aln Buffer

In this study, we compared the device performance of GaInN-based green LEDs grown on c-plane sapphire substrates with a conventional low temperature GaN buffer layer to those with a sputtered-AlN buffer layer. The light output power and leakage current characteristics were significantly improved by just replacing the buffer layer with a sputtered-AlN layer. To understand the origin of the improvement in performance, the electrical and optical properties were compared by means of electro-reflectance spectroscopy, I–V curves, electroluminescence spectra, L–I curves, and internal quantum efficiencies. From the analysis of the results, we concluded that the improvement is mainly due to the mitigation of strain and reduction of the piezoelectric field in the multiple quantum wells active region.

scholarly journals Improved Performance of GaN-Based Light-Emitting Diodes Grown on Si (111) Substrates with NH3 Growth Interruption

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 399
Author(s):  
Sang-Jo Kim ◽  
Semi Oh ◽  
Kwang-Jae Lee ◽  
Sohyeon Kim ◽  
Kyoung-Kook Kim
Keyword(s):  
Buffer Layer ◽  
Light Emitting Diodes ◽  
Defect Density ◽  
Strain Relaxation ◽  
Multiple Quantum Well ◽  
Light Output ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Growth Interruption ◽  
Aln Buffer

We demonstrate the highly efficient, GaN-based, multiple-quantum-well light-emitting diodes (LEDs) grown on Si (111) substrates embedded with the AlN buffer layer using NH3 growth interruption. Analysis of the materials by the X-ray diffraction omega scan and transmission electron microscopy revealed a remarkable improvement in the crystalline quality of the GaN layer with the AlN buffer layer using NH3 growth interruption. This improvement originated from the decreased dislocation densities and coalescence-related defects of the GaN layer that arose from the increased Al migration time. The photoluminescence peak positions and Raman spectra indicate that the internal tensile strain of the GaN layer is effectively relaxed without generating cracks. The LEDs embedded with an AlN buffer layer using NH3 growth interruption at 300 mA exhibited 40.9% higher light output power than that of the reference LED embedded with the AlN buffer layer without NH3 growth interruption. These high performances are attributed to an increased radiative recombination rate owing to the low defect density and strain relaxation in the GaN epilayer.

scholarly journals Zigzag and Helical AlN Layer Prepared by Glancing Angle Deposition and Its Application as a Buffer Layer in a GaN-Based Light-Emitting Diode

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Lung-Chien Chen ◽  
Ching-Ho Tien ◽  
Liu Xuguang ◽  
Xu Bingshe
Keyword(s):  
Buffer Layer ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Light Output ◽  
Glancing Angle Deposition ◽  
Three Dimensional Model ◽  
Light Emitting ◽  
Glancing Angle ◽  
Aln Buffer ◽  
Angle Deposition

This study investigates an aluminum nitride (AlN) nanorod structure sputtered by glancing angle deposition (GLAD) and its application as a buffer layer for GaN-based light-emitting diodes (LEDs) that are fabricated on sapphire substrates. The ray tracing method is adopted with a three-dimensional model in TracePro software. Simulation results indicate that the zigzag AlN nanorod structure is an optimal buffer layer in a GaN-based LED. Furthermore, the light output power of a GaN-based LED with a zigzag AlN nanorod structure improves to as much as 28.6% at a forward current of 20 mA over that of the GaN-based LED with a normal AlN buffer layer.

UV Emission Mechanisms in Quaternary AlInGaN Epilayers and Multiple Quantum Wells

2002 ◽  
Vol 722 ◽  
Author(s):  
Mee-Yi Ryu ◽  
C. Q. Chen ◽  
E. Kuokstis ◽  
J. W. Yang ◽  
G. Simin ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diode ◽  
Chemical Vapor ◽  
Excitation Power ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Excitation Power Density ◽  
Light Emitting ◽  
Uv Emission ◽  
Alloy Disorder

AbstractWe present the results on investigation and analysis of photoluminescence (PL) dynamics of quaternary AlInGaN epilayers and AlInGaN/AlInGaN multiple quantum wells (MQWs) grown by a novel pulsed metalorganic chemical vapor deposition (PMOCVD). The emission peaks in both AlInGaN epilayers and MQWs show a blueshift with increasing excitation power density. The PL emission of quaternary samples is attributed to recombination of carriers/excitons localized at band-tail states. The PL decay time increases with decreasing emission photon energy, which is a characteristic of localized carrier/exciton recombination due to alloy disorder. The obtained properties of AlInGaN materials grown by a PMOCVD are similar to those of InGaN. This indicates that the AlInGaN system is promising for ultraviolet applications such as the InGaN system for blue light emitting diode and laser diode applications.

Control of Barrier Width in Perovskite Multiple Quantum Wells for High Performance Green Light–Emitting Diodes

2018 ◽  
Vol 7 (3) ◽  
pp. 1801575 ◽  
Author(s):  
Maotao Yu ◽  
Chang Yi ◽  
Nana Wang ◽  
Liangdong Zhang ◽  
Renmeng Zou ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Performance ◽  
Light Emitting Diodes ◽  
Green Light ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Barrier Width ◽  
Light Emitting

Two distinct carrier localization in green light-emitting diodes with InGaN/GaN multiple quantum wells

2014 ◽  
Vol 115 (8) ◽  
pp. 083112 ◽  
Author(s):  
Zhi Li ◽  
Junjie Kang ◽  
Bo Wei Wang ◽  
Hongjian Li ◽  
Yu Hsiang Weng ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diodes ◽  
Green Light ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Carrier Localization ◽  
Light Emitting

scholarly journals A 3 W High-Voltage Single-Chip Green Light-Emitting Diode with Multiple-Cells Network

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
W. Wang ◽  
Y. Cai ◽  
Y. B. Zhang ◽  
H. J. Huang ◽  
W. Huang ◽  
...  
Keyword(s):  
High Voltage ◽  
Light Emitting Diode ◽  
Light Output ◽  
Green Light ◽  
Current Crowding ◽  
Single Chip ◽  
Light Output Power ◽  
Large Area ◽  
Light Emitting ◽  
Multiple Cells

A parallel and series network structure was introduced into the design of the high-voltage single-chip (HV-SC) light-emitting diode to inhibit the effect of current crowding and to improve the yield. Using such a design, a6.6×5 mm2large area LED chip of 24 parallel stages was demonstrated with 3 W light output power (LOP) at the current of 500 mA. The forward voltage was measured to be 83 V with the same current injection, corresponding to 3.5 V for a single stage. The LED chip’s average thermal resistance was identified to be 0.28 K/W by using infrared thermography analysis.

Multi-Wavelength Emitting InGaN/GaN Quantum Well Grown on V-Shaped GaN(1101) Microfacet

2007 ◽  
Vol 7 (11) ◽  
pp. 4053-4056 ◽  
Author(s):  
Eun-Sil Kang ◽  
Jin-Woo Ju ◽  
Jin Soo Kim ◽  
Haeng-Keun Ahn ◽  
June Key Lee ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Light Emitting Diode ◽  
Multiple Quantum ◽  
Continuous Change ◽  
Light Emitting ◽  
Transmission Electron ◽  
Luminescence Peak ◽  
Multi Wavelength ◽  
Upward Direction ◽  
Conventional Photolithography

InGaN/GaN multiple quantum wells (MQWs) were successfully grown on the inclined GaN(1101) microfacets. Conventional photolithography and subsequent growth of GaN were employed to generate the V-shaped microfacets along 〈1120〉 direction. The well-developed microfacets observed by scanning electron microscopy and the clear transmission electron microscope interfacial images indicated that the MQW was successfully grown on the GaN microfacets. Interestingly, cathodoluminescence (CL) spectra measured on the microfacets showed a continuous change in the luminescence peak positions. The CL peaks were shifted to a longer wavelength from 420 nm to 440 nm as the probing points were changed along upward direction. This could be attributed to the non-uniform distribution of the In composition and/or the wavefunction overlapping between adjacent wells. Present works thus propose a novel route to fabricate a monolithic white light emitting diode without phosphors by growing the InGaN/GaN MQWs on (1101) facet.

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