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.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0821109-035309 |
| Date | 21 August 2009 |
| Creators | Cheng, Yu-sung |
| Contributors | Chih-Chien Lee, Yu-Kai Han, Jui-Ming Yeh, Ping-Tsung Huang, Mei-Ying Chang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0821109-035309 |
| Rights | campus_withheld, Copyright information available at source archive |
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