Effect of residual stress on the electrical activity of dislocations in GaN light emitting diodes

2012 ◽  
Vol 52 (9-10) ◽  
pp. 2039-2042
Author(s):  
T. Nshanian ◽  
P.N. Grillot ◽  
M. Holub ◽  
S. Watanabe ◽  
W. Götz
Keyword(s):  
Residual Stress ◽  
Electrical Activity ◽  
Light Emitting Diodes ◽  
Light Emitting

Temperature dependence of the electrical activity of localized defects in InGaN-based light emitting diodes

2006 ◽  
Vol 89 (4) ◽  
pp. 041917 ◽  
Author(s):  
M. Pavesi ◽  
M. Manfredi ◽  
F. Rossi ◽  
M. Meneghini ◽  
E. Zanoni ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Temperature Dependence ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Localized Defects

scholarly journals Deposition of Silicon-Based Stacked Layers for Flexible Encapsulation of Organic Light Emitting Diodes

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1053 ◽  
Author(s):  
Chia-Hsun Hsu ◽  
Yang-Shih Lin ◽  
Hsin-Yu Wu ◽  
Xiao-Ying Zhang ◽  
Wan-Yu Wu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Inductively Coupled Plasma ◽  
Light Emitting Diodes ◽  
Silicon Oxide ◽  
Transmission Rate ◽  
Chemical Vapor ◽  
Gas Diffusion ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

In this study, inorganic silicon oxide (SiOx)/organic silicon (SiCxHy) stacked layers were deposited by a radio frequency inductively coupled plasma chemical vapor deposition system as a gas diffusion barrier for organic light-emitting diodes (OLEDs). The effects of thicknesses of SiOx and SiCxHy layers on the water vapor transmission rate (WVTR) and residual stress were investigated to evaluate the encapsulation capability. The experimental results showed that the lowest WVTR and residual stress were obtained when the thicknesses of SiOx and SiCxHy were 300 and 30 nm, respectively. Finally, different numbers of stacked pairs of SiOx/SiCxHy were applied to OLED encapsulation. The OLED encapsulated with the six-pair SiOx/SiCxHy exhibited a low turn-on voltage and low series resistance, and device lifetime increased from 7 h to more than 2000 h.

Injecting Inter-Layers and the Built-in Potential of Blue Polymer Light-Emitting Diodes

2000 ◽  
Vol 660 ◽  
Author(s):  
Thomas M. Brown ◽  
Ian S. Millard ◽  
David J. Lacey ◽  
Jeremy H. Burroughes ◽  
Richard H. Friend ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Basic Structure ◽  
Thin Layers ◽  
Carrier Injection ◽  
Semiconducting Polymer ◽  
Light Emitting ◽  
Physical Mechanisms ◽  
Organic Solid ◽  
Polymer Light Emitting Diodes

ABSTRACTThe semiconducting-polymer/injecting-electrode heterojunction plays a crucial part in the operation of organic solid state devices. In polymer light-emitting diodes (LEDs), a common fundamental structure employed is Indium-Tin-Oxide/Polymer/Al. However, in order to fabricate efficient devices, alterations to this basic structure have to be carried out. The insertion of thin layers, between the electrodes and the emitting polymer, has been shown to greatly enhance LED performance, although the physical mechanisms underlying this effect remain unclear. Here, we use electro-absorption measurements of the built-in potential to monitor shifts in the barrier height at the electrode/polymer interface. We demonstrate that the main advantage brought about by inter-layers, such as poly(ethylenedioxythiophene)/poly(styrene sulphonic acid) (PEDOT:PSS) at the anode and Ca, LiF and CsF at the cathode, is a marked reduction of the barrier to carrier injection. The electro- absorption results also correlate with the electroluminescent characteristics of the LEDs.

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

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.

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