Changes in electron and hole traps in GaN-based light emitting diodes from near-UV to green spectral ranges

2017 ◽  
Vol 110 (19) ◽  
pp. 192107 ◽  
Author(s):  
In-Hwan Lee ◽  
A. Y. Polyakov ◽  
N. B. Smirnov ◽  
R. A. Zinovyev ◽  
Kang-Bin Bae ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Spectral Ranges ◽  
Electron And Hole Traps

Deep Electron and Hole Traps in Electron-Irradiated Green GaN/InGaN Light Emitting Diodes

2017 ◽  
Vol 6 (10) ◽  
pp. Q127-Q131 ◽  
Author(s):  
In-Hwan Lee ◽  
A. Y. Polyakov ◽  
N. B. Smirnov ◽  
I. V. Shchemerov ◽  
Tae-Hoon Chung ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Light Emitting ◽  
Electron And Hole Traps

GIANT MAGNETO-ELECTROLUMINESCENCE FROM HYBRID SPIN-ORGANIC LIGHT EMITTING DIODES

SPIN ◽  
2014 ◽  
Vol 04 (01) ◽  
pp. 1450002 ◽  
Author(s):  
DALI SUN ◽  
TEK P. BASEL ◽  
BHOJ R. GAUTAM ◽  
WEI HAN ◽  
XIN JIANG ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Room Temperature ◽  
Light Emitting Diodes ◽  
Magnetic Tunnel Junction ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light ◽  
Organic Devices ◽  
Spectral Ranges ◽  
Magneto Resistance

An important application that may boost the use of magnetic-field controlled organic devices is significant magnetically modulated electroluminescence (MEL) at room temperature (RT). Whereas inorganic magnetic tunnel junctions show RT magneto-resistance (MR)> 80%, these devices do not exhibit electroluminescence. In contrast, organic light-emitting diodes (OLED) show substantive electroluminescence. Alas, at RT both organic spin valves and spin-OLEDs have shown rather small MR and MEL. We report here a hybrid organic/inorganic magnetic-field controlled device (h-OLED) which comprises of an inorganic magnetic tunnel junction with large room temperature MR, and OLED having efficient electroluminescence. At RT the h-OLED devices exhibit up to 80% giant MEL in the red, green, and blue spectral ranges. Moreover studies of "white" h-OLED devices show a surprising magnetic-field controlled color manipulation. The h-OLED devices may open a new avenue in the application of multifunctional organic displays.

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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