scholarly journals Thermal droop in III-nitride based light-emitting diodes: Physical origin and perspectives

2020 ◽  
Vol 127 (21) ◽  
pp. 211102 ◽  
Author(s):  
Matteo Meneghini ◽  
Carlo De Santi ◽  
Alberto Tibaldi ◽  
Marco Vallone ◽  
Francesco Bertazzi ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Physical Origin ◽  
Light Emitting ◽  
Thermal Droop

Role of defects in the thermal droop of InGaN-based light emitting diodes

2016 ◽  
Vol 119 (9) ◽  
pp. 094501 ◽  
Author(s):  
C. De Santi ◽  
M. Meneghini ◽  
M. La Grassa ◽  
B. Galler ◽  
R. Zeisel ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Thermal Droop

Reduction in Thermal Droop Using Thick Single-Quantum-Well Structure in Semipolar ($20\bar{2}\bar{1}$) Blue Light-Emitting Diodes

2012 ◽  
Vol 5 (10) ◽  
pp. 102103 ◽  
Author(s):  
Chih-Chien Pan ◽  
Tao Gilbert ◽  
Nathan Pfaff ◽  
Shinichi Tanaka ◽  
Yuji Zhao ◽  
...  
Keyword(s):  
Quantum Well ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Single Quantum ◽  
Single Quantum Well ◽  
Light Emitting ◽  
Quantum Well Structure ◽  
Thermal Droop

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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