Browsing by Author "Liao, Chi-Hung"

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Highly efficient blue organic light-emitting devices incorporating a composite hole transport layer
(2005-01-01)
Liao, Chi-Hung
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Lee, Meng-Ting
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Chen, Chin H.
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應用化學系
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Department of Applied Chemistry
Organic light-emitting devices (OLEDs) incorporating the copper phthalocyanine (CuPc)/N,N'-bis-(1-naphthyl)-N,N'-diphenyl, 1,1'-biphenyl-4,4'-diamine (NPB) composite hole transport layer (c-HTL) have been fabricated. Under optimal condition, the amino-subsituted distyrlarylene fluorescent dye (DSA-Ph), doped in the stabel diarylanthracene blue host (MADN) achieved a luminance efficiency of 16.2 cd/A with a CIEx,y color coordinate of [0.15, 0.29] at 6.44 V (20 mA/cm(2)), which is one of the best ever reported to date.
Highly stable organic light emitting devices based on uniformly mixed hole transport layer
(2005)
Tsai, Chih-Hung
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Liao, Chi-Hung
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Chen, Chin-H.
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友訊交大聯合研發中心
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D Link NCTU Joint Res Ctr
High stable organic light emitting devices (OLEDs) can be achieved by using an Uniformly Mixed Hole transport layer (UM-HTL) composed of a mixture of 2-methyl-9,10-di(2-naphthyl)anthracene (MADN) with N,N'-bis(1-naphthyl)-N,N'-diphenyl, 1,1'-biphenyl-4, 4'-diamine (NPB) in a 4:6 ratio of MADN:NPB. Compared to OLEDs using the conventional structure (t(90) = 1500 h) the lifetime of green tris(8-hydroxyquinoline) aluminum (Alq(3)) device using the UM-HTL can be improved to about 3 times (t(90) = 4420 h). Consequently utilizing the UM-HTL in OLEDs can effectively depress device degradation without impacting on the driving voltage and the color saturation significantly.
Improved stability of C-545T doped green OLEDs
(2005)
Lee, Meng-Ting
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Liao, Chi-Hung
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Tsai, Chih-Hung
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Chen, Chin-H.
;
應用化學系
The stability of C-545T doped green organic electroluminescent device (OLED) has been improved by doping styrylamine derivate, p-bis(p-N,N-diphenyl-aminostyryl)benzene (DSA-Ph) benzene (DSA-Ph) in hole transporting layer, the device configuration abbreviated as BHTL. Compared with the undoped device, the stability of the BHTL device has increased by a factor of 1.3 without affecting the electroluminescence (EL) efficiency of 11 cd/A and color (CIEx,y = 035, 0.61). The enhanced stability is believed to derive from the hole trapping nature of DSA-Ph which can reduce the residual hole carriers in tris(8-hydroquinolinato)aluminum (Alq(3)) and suppress the formation of florescent quencher of Alq(3) cationic species.
Novel silane-based blue dopant for organic electroluminescent devices
(2005)
Yeh, Chih-Ming
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Lee, Meng-Ting
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Liao, Chi-Hung
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Chen, Chin H.
;
應用化學系
We have synthesized a new deep blue dopant (JTI) based on organic Silane fluorescent dye. Owing to the steric hindered characteristic of Silane moiety, the problem of dopant concentration quenching can be suppressed. When JTI was doped up to 15% in the stable blue host material 2-JTI JTI was doped up to 15% in the stable blue host material 2-methyl -9,10-di(2-naphthyl a luminance yield of 3.93 cd/A at 20 mA/cm(2) with a near saturated CIEx,y color coordinate of [0.15, 0.15].
Optoelectronic Properties of Single-Crystalline Zn2GeO4 Nanowires
(2014-04-17)
Liao, Chi-Hung
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Huang, Chun-Wei
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Chen, Jui-Yuan
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Chiu, Chung-Hua
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Tsai, TzungChuen
In this work, Zn2GeO4 nanowires (NWs) were successfully synthesized on Si(100) substrates through carbon thermal reduction and a vapor liquid solid method. The NWs were of around 100 nm diameter and high aspect ratio (AR > 150). High-resolution transmission electron microscopy studies indicate that the NWs are single-crystalline with [110] growth direction. Moreover, the atomic resolution high-angle annular dark-field and bright-field images of scanning transmission electron microscopy have distinguished the different elements. They also further identified the structure of Zn2GeO4 and located the positions of the elements. Additionally, we have fabricated devices and measured the electrical properties of a single NW. It is remarkable that individual Zn2GeO4 NW devices exhibited excellent optoelectronic properties with fast switching speed under 254 nm UV illuminations. Furthermore, with short wavelength UV illumination, as we soaked Zn2GeO4 NWs in methyl orange solution, the methyl orange was degraded. Therefore, Zn2GeO4 NWs have potential applications in UV photodetectors and degradation of organic pollutants.