Browsing by Author "Cheng, Jung-An"

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Adaptive current scaling pixel circuit for a-Si : H AMOLED
(2005)
Huang, Jian-Zhi
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Cheng, Jung-An
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Lin, Yen-Chung
;
Cheng, Wayne
;
Shieh, Han-Ping D.
An adaptive current scaling pixel circuit for a-Si:H TFT process has been demonstrated. The adaptive current scaling is achieved by insetting a small cascaded storage capacitor to the traditional pixel circuit without affecting the aperture ratio. The proposed pixel circuit is capable of shorting the programming time without sacrificing the power consumption. Hence, the proposed pixel circuit is suitable for the large size and high resolution AMOLED application.
Black matrices surface treatment for color filters ink jet printing process
(2007)
Shin, You-Ru
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Wu, Siang-Jhih
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Cheng, Jung-An
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Chen, Huang-Ming P.
;
Li, Huai-An
An inkjet printing process for color filter fabrication is one of key technologies for next generation processes. To prevent ink overflow from the black matrices (BM) bank, two effective surface pre-treatments were introduced in this study. The contact angle of chemical treatment and CFx plasma treatment can be increased from 12 to 52 degrees and 12 to 27 for red ink, respectively.
Color filtering functional organic thin-film transistors
(2007)
Huang, Yu-Jen
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Chang, Hsiao-Fen
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Tsai, Shu-Ting
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Chuang, Chiao-Shun
;
Cheng, Jung-An
The colored insulators were utilized as the color filter and the dielectric layer of the OTFTs simultaneously to obtain the desired color. This work was successfully integrated gate insulator and color filter, which offered an ink-jet printing compatible process for cost-effective fabrication of liquid-crystal displays.
Controllable carrier density of pentacene field-effect transistors using polyacrylates as gate dielectrics
(2008-12-01)
Cheng, Jung-An
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Chuang, Chiao-Shun
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Chang, Ming-Nung
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Tsai, Yan-Chu
;
Shieh, Han-Ping D.
We have studied the effect of the chemical structure of dielectrics by evaporating pentacene onto a series of polyacrylates: poly(methylmethacrylate), poly(4-methoxyphenylacrylate), poly(phenylacrylate), and poly(2,2,2-trifluoroethyl methacrylate) in organic thin-film transistors (OTFTs). In top-contact OTFTs, the polyacrylates had a significant effect on field-effect mobilities ranging 0.093 similar to 0.195 cm(2) V-1 s(-1). This variation neither correlated with the polymer surface morphology nor the observed pentacene crystallite size. This result implies that the PTFMA device generates the local electric field that accumulates holes and significantly shifts the threshold voltage and the turn-on voltage to -8.62 V and 3.5 V, respectively, in comparison with those of PMMA devices. (C) 2008 Elsevier B.V. All rights reserved.
Controllable Surface Plasmon Rasonance in Gold Nanocomposites for Organic Light-Emitting Diodes
(2011)
Chang, Chia-Ying
;
Lin, Yung-Lun
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Cheng, Pi-Ju
;
Cheng, Jung-An
;
Chang, Shu-Mei
The water dispersible gold nanoparticles coordinated with various surfactants for surface plasmon enhancement were synthesized. Via modulating the refractive indexes of surfactants, the surface plasmon resonance wavelength can be varied between 520 and 570 nm. As a result, Au nanoparticles-incorporated PEDOT:PSS matrix layer revealed a 2.7x increase in fluorescence quantum yields from fluorescent dye, P2-A.
Crystal Study of N,N '-diphenyl-N,N '-bis(1-naphthyl)-1,1 '-biphenyl-4,4 '-diamine
(2010-06-01)
Cheng, Jung-An
;
Cheng, Pi-Ju
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光電工程學系
;
顯示科技研究所
;
Department of Photonics
The structure of N,N'-diphenyl-N,N'-bis(1-naphthyl)- 1,1'-biphenyl-4,4'-diamine (NPB) with two molecules in the asymmetric unit, was solved and refined to a final R factor of 0.0434. The compound crystallized in the triclinic crystal system, space group P - 1, Z = 2, V = 1597.0(3) angstrom(3) with unit cell parameters a = 10.3077(10) angstrom, b = 11.3545(11) angstrom, c = 14.4778(14) angstrom, alpha = 82.339(2)degrees, beta = 77.657(2)degrees, and gamma = 75.526(2)degrees. The two molecules in the asymmetric unit differed in the orientation of their triarylamino groups. The biphenyl group in the central structure is coplanar, and the angle between the least-square planes of the two six-carbon rings of the biphenyl moiety is zero degree. The packing of the molecules in the lattice is mainly due to the naphthyl-to-naphthyl pi-pi interaction with a distance of 3.861 angstrom.
Enhanced field-effect mobility in pentacene based organic thin-film transistors on polyacrylates
(2009-03-15)
Cheng, Jung-An
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Chuang, Chiao-Shun
;
Chang, Ming-Nung
;
Tsai, Yun-Chu
;
Shieh, Han-Ping D.
We reported on organic thin-film transistors (OTFTs) with high dielectric constant polymer, poly(2,2,2-trifluoroethyl methacrylate) (PTFMA), as the gate dielectric. In top-contact OTFTs, the field-effect mobility was enhanced by applying a dielectric buffer layer poly(alpha-methylstyrene) to the bare PTFMA. After improving interfacial affinity within the active layer/dielectrics, deposited pentacene grain size and device performance were enhanced dramatically. The corresponding mobility, threshold voltage, and on/off current ratio were 0.70 cm(2) V(-1) s(-1), -10.5 V, and 5.4x10(5), respectively. The moderately improved interface also suppressed the hole-trapping effect, which led to less hysteresis and minimized threshold voltage shift.
Large area color filter fabrication by using ink-jet printing technology
(2008)
Wu, Siang-Jhih
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Cheng, Jung-An
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Chen, Huang-Ming P.
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Shin, You-Ru
;
Shieh, Han-Ping D.
A novel ink jet printing process without additional photolithography process for large area color filter fabrication has been developed in this study. A 100x100 mm(2) model of 32" color filters was fabricated for evaluation. New developed RGB inks were able to achieve 73% NTSC standard with the thickness of R, G, and B films at 1.80, 1.90, and 1.80 pm, respectively. The overflow issue can be solved by surface pretreatments, and color inks formulation.
Microlens array by ink-jet technology for LCD backlight applications
(2008)
Hung, Chien-Hsiang
;
Yu, Tsung-Han
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Cheng, Jung-An
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Chang, Chi-Hsien
;
Hsiau, Yi-Hau
This research uses Ink-jet printer process to fabricate microlens on the bottom of a LGP in a fast and cost-effective way. Compared with typical dot printing method, Ink-jet printing is able to save 50% material consumption. In addition, the microlens with UV-curable epoxy could be well controlled in the radius, contact angle and arbitrary arrangement. A 20x20cm(2) LGP can be fabricated with desired microlens pattern within 10 seconds, which exhibits a potential to apply ink-jet process upon the high-speed mass production.
Organic light-emitting devices based on solution-processible quinolato-complex supramolecules
(2009-02-15)
Cheng, Jung-An
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Chen, Chin H.
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Shieh, Han-Ping D.
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光電工程學系
;
顯示科技研究所
This paper discusses a new type of supramolecular material tris{5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl)aminesulfonyl-8-hydroxyquinolato} aluminum(III), Al(SCarq)(3), which we synthesized using three 5-N-[3-(9H-carbazol-9-yl)propyl]-N-(4-methylphenyl)aminesulfonyl-8-hydroxyquinoline as bidentate ligands. The peak photoluminescence in the solid phase appears at 488 nm. In cyclic voltammetric measurement, two oxidation peaks, which were obtained at -5.6 and -5.9eV, correspond to HOMO sites of carbazoyl and aluminum quinolates, respectively. in the investigation of solid morphological thin film, the flat surface was investigated using an atomic force microscope. The root mean square (rms) and mean roughness (R(a)) were respectively measured to be 0.427 and 0.343 nm. For the fabrication of organic light-emitting devices (OLEDs) using spin-coating techniques, the turn-on voltage and maximum luminescence of the optimized electroluminescence device, glass/ITO (20 nm)/PEDOT: PSS (75 nm)/Al(SCarq)(3) (85 nm)/BCP (8 nm)/LiF (1 nm)/Al (200 nm), were respectively 9.6 V and 35.0 cd m(-2). Due to the electroplex formation between the carbazole (electron-donor) and the aluminum quinolates (electron-acceptor) moieties under an applied DC bias, the chromaticity of electroluminescence shifted to green-yellow with 1931 CIE(x,y) (0.40, 0.47). (C) 2008 Elsevier B.V. All rights reserved.
Organic thin film transistors with novel solution-process polymeric gate insulators
(2007)
Tsai, Yan-Chu
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Tsai, Shu-Ting
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Chuang, Chiao-Shun
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Cheng, Jung-An
;
Chen, Fang-Chung
Novel OTFTs polymeric gate dielectric insulators derived from PMMA and PVP, named PHE, POH and F3, were demonstrated. By using the novel insulators, those OTFTs showed acceptable electrical characteristics including higher on/off ratio of five order of magnitude, low subthreshold swing about 2 V/decade and mobility around 0.1 cm(2)/Vs. F3 based devices, especially have the most stable I-V and C-V characteristics to replace PVP.
Organic thin-film transistors with color filtering functional gate insulators
(2008-08-04)
Chuang, Chiao-Shun
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Cheng, Jung-An
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Huang, Yu-Jen
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Chang, Hsiao-Fen
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Chen, Fang-Chung
We developed color filtering functional organic thin-film transistors exhibiting both high field-effect mobilities and color-filtering ability. The conventional colorant inks were utilized as the materials for the color filter/dielectric multifunction layers. In order to improve the electrical performance, a high dielectric polymeric insulator, poly(2,2,2-trifluoroethyl methacrylate), was introduced to modify the surface of the dielectric layer. Further, the Commission Internationale de L'Eclairage chromaticity coordinates were (0.64, 0.34), (0.36, 0.54), and (0.14, 0.15) for red, green, and blue devices, respectively, covering 49.2% National Television Systems Committee standard. This work represents one potential example for multifunctional organic electronics. (C) 2008 American Institute of Physics.
Pyrolysis behavior of blue Alq(3) derivatives in thermal process
(2006)
Cheng, Jung-An
;
Yang, Yixin
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Chen, Chin H.
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Shieh, Han-Ping D.
;
Negishi, Toshio
In order to study the blue and soluble Alq(3)-based derivates that fail to sublimate, a series of developable solutions and thermally stable aluminum quinolates with different sulfon reactants were synthesized. The physical and chemical attributes of these chelates were investigated and thoroughly characterized by using the X-ray diffraction method, H-1 NMR and thermal gravity analysis. In this study we also explored the mechanisms involved in the thermal decomposition that occurs during the sublimation process.
Rib-free Ink-Jet Printing Fabrication on Heterogeneous Surfaces
(2010)
Chen, Huang-Ming P.
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Wu, Siang-Jhih
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Tong, Feng-Ching
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Cheng, Jung-An
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Shieh, Han-Ping D.
Rib-free ink-jet printing device fabrication on hetrogeneous surfaces opens a new possibility for greener processes. The integrity of ink droplets was maintained with less than 3 degrees contact angle differences on the heterogeneous surfaces after surface treatment. The breaking of color lines and color mixing were avoided by accelerating solvent evaporation. The inks were greatly conserved without the need for additional lithography process for rib structure. (C) 2010 The Japan Society of Applied Physics
Rib-less Ink-Jet-Printed 4-in.-Panel Color-Filter Fabrication
(2009)
Chen, Huang-Ming P.
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Wu, Siang-Jhih
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Cheng, Jung-An
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Tong, Feng-Ching
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Shieh, Han-Ping D.
A 4 "color filter panel was successfully prepared by rib-less ink jet printing process. The smeared ink issue can be controlled by surface treatment on both Cr and glass with similar contact angle. The color line formation can be prepared by either two-step printing process at room temperature or one-step printing at elevated temperature. The thickness of red, green and blue films were about 1.2 mu m, 1.0 mu m and 1.0 mu m, respectively. The panel's NTSC value was estimated at 53.5 +/- 0.7%.
Solution-processible organic light-emitting device based on quinolato-complex supramolecules
(2005)
Cheng, Jung-An
;
Chen, Chin H.
;
Shieh, Han-Ping D.
;
光電工程學系
;
Department of Photonics
A new type of supramolecular light-emitting materials Al(SCarq)(3) was synthesized by 5-N-(3-carbazylpropyl)-p-methylaniline-sulfonyl-8-hydroxyquinoline. Via molecular engineering, its solid photoluminescence shows blue-green at 488 nm and two HOMO sites were -5.44 and -5.93 eV. For OLEDs fabrication using spin-coating techniques, the turn-on voltage and the maximum luminescent were 9.6 V and 35.0 cd/m(2), respectively. Due to the electroplex formation, the chromaticity of EL was shifted to green-yellow with 1931 CIEx,y (0.40, 0.47).
Surface Plasmon Mediated Luminescent Enhancement of Polymer LEDs Using Dual-functional Hole-Injection Layer
(2009)
Cheng, Pi-Ju
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Cheng, Jung-An
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Lin, Zong-Wei
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Tien, Chung-Hao
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光電工程學系
A hole-injection-layer in PLED with a plasmonic metal nanostructure was demonstrated. Dual-functional Au nanoparticles-incorporated PEDOT:PSS matrix layer revealed a 2.3x increase in fluorescence quantum yields from MEH-PPV, via dipolar surface plasmon resonance. With an additional spacer layer, the nanocompostie layer remarkably enhanced the PL intensity of MEH-PPV more than ten fold.
The influence of ITO pretreatment on the organic light-emitting device stability and efficiency
(2007)
Cheng, Jung-An
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Chang, Ming-Nung
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Chen, Chin H.
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Shieh, Han-Ping D.
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Negishi, Toshio
The influence of ITO pretreatment and its OLED devices were investigated. It was found that the lifetime and EL efficiency are strongly depended on the ITO cleaning and its surface morphology. In the result, the lifetime and EL performance in our demonstrated devices were significantly enhanced.
Transparent OTFTs with color filtering functional gate insulators
(2007)
Chuang, Chiao-Shun
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Tsai, Shu-Ting
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Lin, Yung-Sheng
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Cheng, Jung-An
;
Chen, Fang-Chung
Transparent organic thin-film transistors (OTFTs) impregnated with nanoparticles, organic dyes and pigments in the dielectric insulators were fabricated and analyzed. The colored composite insulators were utilized as the color filter and the dielectric layer of the OTFTs simultaneously to obtain the desired color. It was found that the performance the OTFTs with the above mentioned composite dielectric layers possess color filtering comparable to the conventional devices. In addition, light sensitivity of OTFTs was significantly reduced.