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The characteristic of 1,3,5-Tri(1-pyrenyl)benzene(TPB3) and the performance of organic light-emitting deviceCheng, Yu-sung 21 August 2009 (has links)
It has been found that the results of 1,3,5-Tri(1-pyrenyl)benzene
(TPB3) on the processing conditions of different depositon rates affect
the morphology of thin films and the electroluminescent performance of
the devices. At TPB3 deposition low rate, the average roughness of
TPB3 thin film was much smoother comparing to high rate, the surface
approached morphology and the wavelength peak was around 508nm. At
TPB3 deposition high rate, the surface approached amorphous and the
wavelength peak was around 476nm. Take advantage of varing deposition
rates with different spectra to apply for colorful OLEDs.
This research includes three parts as mentioned: (1) red organic light-emitting devices and (2) green organic light-emitting devices and (3) white organic light-emitting devices.
In order to overlap perfectly between the host and dopant materials, we fabricated the red organic electroluminescent devices incorporating TPB3 at deposition low rate as the host material and 4-(dicyanomethylene
)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) as red light-emitting dye and the green organic electroluminescent devices incorporating TPB3 at deposition high rate as the host material and 2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H,5H,11H-10(2-
benzothiazolyl)quinolizine-[9,9a,1gh]coumarin (C545T) as green light-emitting dye, respectively.
First, we deposited TPB3 at the lower rate of 0.1 Å/sec as the host material doped the red dopant, DCJTB, for making red OLEDs. The device: ITO(130nm)/NPB(65nm)/TPB3: 2% DCJTB(40nm)/Alq3(30nm) /LiF(0.8nm)/Al(200nm) exhibited a maximum luminance at 13.5V of 70600 cd/m2, ca. four times higher than that of the device using Alq3 as the host material at the same potential. The maximum current and power efficiencies were 4.83 cd/A and 3.7 lm/W, respectively. The current and power efficiencies were greater than 4 cd/A and 1 lm/W, respectively, over the large range of potentials (3.5~13.5V) with good Commission Internationale de l¡¦Eclairage (CIE) coordinates of (0.63,0.37). These results indicate that searching for a suitable host material is a promising approach toward achieving high-efficiency red OLEDs.
The second, we deposited TPB3 at the higher rate of 3.0 Å/sec as the host material doped the green dopant C545T in order to overlap perfectly between them for spectra in green OLEDs. The device: ITO(130nm) /NPB(65nm) /TPB3: 1%C545T(40nm) /Alq3(30nm) /LiF(0.8nm)
/Al(200nm) exhibited a maximum luminance at 11.5V of 166000 cd/m2, it¡¦s higher than that of the device using Alq3 as the host material at the same potential. The maximum current and power efficiencies were 10.0 cd/A and 6.67 lm/W, respectively. The current and power efficiencies were greater than 7.98 cd/A and 2.28 lm/W, respectively, over the large range of potentials (4.0~11.0V) with good Commission Internationale de l¡¦Eclairage (CIE) coordinates of (0.31, 0.61). These results indicate that TPB3 OLEDs are good than Alq3 OLEDs..
For TPB3 white OLEDs, we deposited TPB3 at the higher rate of 3.0 Å/sec as the host material doped the red dopant DCJTB in order to make high color purity white OLEDs. The device: ITO(130nm) /NPB(65nm)
/TPB3: 0.05%DCJTB(40nm) /Alq3(30nm) /LiF(0.8nm) /Al(200nm) exhibited a maximum luminance at 11.5V of 55690 cd/m2, the maximum current and power efficiencies were 4.57 cd/A and 3.01 lm/W, respectively. The current and power efficiencies were greater than 3 cd/A and 0.91 lm/W, respectively, over the large range of potentials (3.5~11.5V) with good Commission Internationale de l¡¦Eclairage (CIE) coordinates of (0.34 , 0.34)~(0.33 , 0.33). These results indicate that TPB3 white OLEDs have good luminance and color purity.
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Implementation of ‘Hole confinement’ for efficient Inverted and un-doped bi-layer Organic Light Emitting Diodes using a buffer layerSubramanian, Arunkumar 23 September 2011 (has links)
No description available.
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Development of top-emission Organic Light-Emitting Diodes for High luminance monochrome and full-colour microdisplay applications / Micro-écran OLED pour des systèmes optiques en projectionGohri, Vipul 12 December 2012 (has links)
La travail présente traite du développement de diodes organiques électroluminescentes(OLEDs) a haute luminance pour des applications dans des micro écrans. Ces dispositifs sontbases sur des substrats silicium utilisent la technologie CMOS. Le présent ouvrage met en avantles efforts développe afin de réduire la dérive en tension et ma décroissance lumineuse enopération des dispositifs lumineux.Dans la première partie de l’étude, des OLEDs vertes haute luminance fonctionnant àbasse tension sont développes. L’empilement organique a émission vers le haut comprenant unémetteur fluorescent vert entre des couches de blocage de charges et des couches de transportdopées. Les effets de différentes structures de dispositifs, des configurations de l’empilement etdes matériaux organiques sur les performances initiales et en opération sont reportés ici.Dans la deuxième partie de l’étude, le développement de dispositifs OLED hybrides pourmicro écrans couleurs est présenté. Les structures hybrides comprennent une couche detransport de trous photosensible et traitable par solution (X-HTL) et d’une OLED blancheréalisée par évaporation sous vide. Cette méthode permet la génération de couleur directe, ellepermet ainsi d’obtenir de très bonnes efficacités et un contrôle aisé de la couleur émise parsimple modification de l’épaisseur de X-HTL. / The present work reports the development of high luminance organic light emitting diodes(OLEDs) device stacks for microdisplay applications. The devices are based on siliconcomplementary metal-oxide semiconductor (CMOS) backplane. In the present treatise effortsare particularly focused on reducing the luminance decay and the voltage drift during deviceoperation.In the first part of this study, high brightness and low operating voltage green OLEDs arereported. The top emitting device stack comprises of fluorescent green emitter accompanied bycharge blocking layers and doped charge transport layers. The effect of different devicestructures, configurations and organic materials on the initial and lifetime performance of thedevice is presented.In the second part of the study, device development of hybrid OLED stacks for high luminancefull color microdisplays is reported. The hybrid devices comprise of a solution processed andphotocrosslinkable hole transport layer (X-HTL) and an evaporated white OLED stack. Thismethod allows direct primary color generation with relatively high efficiency and offers ease ofcolor tunability by controlling the thickness of the X-HTL.
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