Study of the spectral and power characteristics of In0.2Ga0.8N/GaN superluminescent light emitting diodes by taking into account the piezoelectric polarization fields

Abstract In this study, the effects of the piezoelectric polarization field have been investigated on the spectral and power characteristics of In0.2Ga0.8N/GaN superluminescent light emitting diodes. The Schrödinger and Poisson equations, the rate equations in the multiple quantum well active region and separate confinement heterostructure layers, and the optical propagating equations have been solved in the presence of the piezoelectric field. The results have been compared with results of the case of without piezoelectric field. According to the results, in the presence of piezoelectric field, the red-shift occurs in the spectra, and the width of spectrum increases. Also, the piezoelectric field decreases the peak intensity of spectrum and modal gain of the device.

Download Full-text

Measurement of the Piezoelectric Field in InGaN/AlGaN Multiple-Quantum-Well Near-Ultraviolet Light-Emitting Diodes by Electroreflectance Spectroscopy

IEEE Journal of Quantum Electronics ◽

10.1109/jqe.2019.2928370 ◽

2019 ◽

Vol 55 (5) ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Abu Bashar Mohammad Hamidul Islam ◽

Jong-In Shim ◽

Dong-Soo Shin

Keyword(s):

Quantum Well ◽

Ultraviolet Light ◽

Light Emitting Diodes ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Light Emitting ◽

Near Ultraviolet ◽

Piezoelectric Field ◽

Electroreflectance Spectroscopy ◽

Ultraviolet Light Emitting Diodes

Download Full-text

Effect of an electron blocking layer on the piezoelectric field in InGaN/GaN multiple quantum well light-emitting diodes

Applied Physics Letters ◽

10.1063/1.3681162 ◽

2012 ◽

Vol 100 (4) ◽

pp. 041119 ◽

Cited By ~ 6

Author(s):

Dong-Yul Lee ◽

Sang-Heon Han ◽

Dong-Ju Lee ◽

Jeong Wook Lee ◽

Dong-Joon Kim ◽

...

Keyword(s):

Quantum Well ◽

Light Emitting Diodes ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Blocking Layer ◽

Electron Blocking Layer ◽

Light Emitting ◽

Piezoelectric Field

Download Full-text

Low-Temperature Operation of Green, Blue and UV InGaN/GaN Multiple-Quantum-Well Light-Emitting Diodes

MRS Proceedings ◽

10.1557/proc-764-c5.5 ◽

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.

Download Full-text

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

Micromachines ◽

10.3390/mi12040399 ◽

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.

Download Full-text