Browsing by Author "Chen, Chen-Ming"

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Comparison of Different Encapsulating Adhesives to Enhance the Efficiencies and Lifetimes of Polymeric Solar Cells
(2009-04-01)
Chung, Ming-Hua
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Chen, Chen-Ming
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Hsieh, Tsung-Eong
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Tang, Rong-Ming
;
Tsai, Yu Sheng
Polymeric solar cells (PSCs) with a derivative of C(60) [[6,6]-phenyl C(61)-butyric acid methyl ester (PCBM)], and 3-hexylthiophene (P3HT) as active layers have been fabricated. The PSC devices were also packaged with glass and novel UV glues to improve their lifetimes and power conversion efficiencies (PCEs). After encapsulation with UV glue I, II, and III, the PCEs of PSCs reached 4, 4.82, and 6%, respectively, and their half-lifetimes increased to 16-18, 26-28, and 90 h, respectively, while the PCEs and half-lifetimes of PSCs without encapsulation were 3.76% and 2.5 h, respectively. (C) 2009 The Japan Society of Applied Physics
Effects of polydispersity index and molecular weight on crystallization kinetics of syndiotactic polystyrene (sPS)
(2009-07-08)
Chen, Chen-Ming
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Hsieh, Tsung-Eong
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Ju, Ming-Yih
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材料科學與工程學系
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Department of Materials Science and Engineering
Isothermal crystallization kinetics of syndiotactic polystyrene (sPS) is reported in this work with Avrami analytical method. it was found that the spherulite growth rate and overall crystallization rate depend on the crystallization temperatures, average molecular weight ((M) over bar (W)) and polydispersity index (PDI). The experimental results for the melt and cold crystallization processes of sPS revealed that the PDI and (M) over bar (W) exhibit pivotal effects on the crystallization rate, which increases with the decrease of (M) over bar (W) and PDI. (C) 2009 Elsevier B.V. All rights reserved.
Electroluminescent properties of color/luminance tunable organic light emitting diodes and their lifetime enhancement with encapsulation
(2008-09-25)
Chen, Chen-Ming
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Chung, Ming-Hua
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Hsieh, Tsung-Eong
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Huang, Bohr-Ran
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Hsieh, Huai-En
In this work, color/luminance tunable organic light emitting diodes (OLEDs) (ITO glass/naphthyl phenyl benzidine (NPB; 80 nm)/4,4'-bis(diphenylvinylenyl)-biphenyl (ADS082BE; 35 nm)/1,3-bis[2-(2,2'-bipyridine-6-yl)-1,3,4-oxadiazo-5-yl]benzene (Bpy-OXD; 20 nm)/tris-[8-hydroxy-quinoline]aluminum (Alq(3); 50 nm)/lithium fluoride (LiF; 3 nm)/aluminum (Al, 80 nm)) with low turn-on voltage (3 V) and high luminance (4850 cd/m(2) at 9 V) have been successfully manufactured. The experimental results reveal that their electroluminescent properties (e.g. hue, luminescent intensity, etc.) can be modulated by the manipulation for the layer thickness of NPB/ADS082BE/Bpy-OXD and the applied voltages. In addition, we have also demonstrated lab-made UV-curable silicone-acrylate encapsulating resin exhibits excellent gas barrier capability so that the half-lifetimes of OLEDs reach 98 h whereas those without encapsulation are only 9 h. (C) 2008 Elsevier B.V. All rights reserved.
Physical properties of syndiotactic polystyrene (sPS)/poly(2,6-dimethyl-1,4-phenylene oxide (PPO) alloys and their feasible estimation for reflective cups of light emitting diodes (LEDs)
(2011-10-20)
Chung, Ming-Hua
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Lin, Jian-Shian
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Hsieh, Tsung-Eong
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Chen, Nien-Po
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Chen, Chen-Ming
In this paper, the effects of antioxidants and processing parameters on the thermal stability and processability of sPS have been investigated. Experimental results indicate that a long processing duration and mechanic shearing force accelerate the thermal oxidation and addition of antioxidants into sPS can effectively improve color contamination and thermal stability. Furthermore, feasible estimation of sPS/PPO alloys for reflective cups of light emitting diodes (LEDs) have also been made, demonstrating that sPS/PPO alloys are potential candidates by the appropriate prescription of impact modifiers, flame retardants, and titanium dioxide. (C) 2011 Elsevier B.V. All rights reserved.
Preparation of epoxy-modified polyethylene by graft extrusion and its applications to polyphenylene sulfide alloys as a compatibilizer
(2008-09-01)
Chen, Chen-Ming
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Hsieh, Tsung-Eong
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Liu, Mark O.
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材料科學與工程學系
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Department of Materials Science and Engineering
Epoxy-modified polyethylene (PE-g-GMA) was successfully synthesized from glycidyl methacrylate (GMA) and low-density polyethylene (LDPE) via the grafting reaction of extrusion. The mechanism of grafting reaction and the rapid determination for the percentage of grafting are also reported. Experimental results demonstrated that the PE-g-GMA is a good compatibilizer in polyphenylene sulfide/poly(ethylene terephthalate) (PPS/PET) as well as PPS/nylon 6,6/glass fiber alloys and the addition of PE-g-GMA into PPS alloys may effectively improve the mechanical properties of composites. (C) 2008 Elsevier Ltd. All rights reserved.
Preparation of organic/inorganic hybrid nanocomposites by ultraviolet irradiation and their packaging applications for organic optoelectronic devices
(2011-08-15)
Chung, Ming-Hua
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Lin, Jian-Shian
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Hsieh, Tsung-Eong
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Chen, Nien-Po
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Juang, Fuh-Shyang
By ultraviolet (UV)-assisted synthetic procedure, we have successfully prepared several UV curable organic/inorganic hybrid nanocomposites with excellent gas barrier capabilities, moderate hardness, and good adhesive strength. The experimental results reveal that the physical properties of nanocomposites depend on their chemical structures. Therefore, introduction of silicone and polyurethane (PU) into the Acrylics backbone dramatically raises the adhesive strength as well as refractive index and lowers the gas penetration. Furthermore, we have also applied lab-made nanocomposite g for the encapsulation of organic optoelectronic devices such as OLEDs, flexible OLEDs, and organic solar cells. With the package of lab-made nanocomposite g, the organic optoelectronic devices effectively resist the entry of moisture and oxygen in the air, extending the lifetimes. (C) 2011 Elsevier B.V. All rights reserved.
Synthesis of poly(4-vinylphenol) (PVPh) and polyhedral oligomeric silsesquioxanes-poly(4-vinylphenol) (POSS-PVPh) with low surface energy and their surface properties
(2011-12-15)
Liao, Chun-Hsiung
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Chien, Fu-Ming
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Chen, Chen-Ming
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Liu, Lung-Chang
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Chung, Ming-Hua
In this paper, we have synthesized poly(4-vinylphenol) (PVPh) and polyhedral oligomeric silsesquioxanes-poly(4-vinylphenol) (POSS-PVPh) with low surface energies and investigated their surface properties. Experimental results reveal that the surface properties of PVPh and POSS-PVPh can be manipulated with the length of PVPh segment and POSS contents, respectively, resulting in the variation of intermolecular hydrogen bonding interactions. In addition, the surface energies of PVPh after thermal treatment of 180 degrees C for 24 h can be less than 20 mJ m(-2) and those of POSS-PVPh without thermal treatment can be less than 25 mJ m-2 while those of poly(tetrafluoroethylene)(PTFE) are 22 mJ m(-2). (C) 2011 Elsevier B.V. All rights reserved.
Synthesis, thermal characterization, and gas barrier properties of UV curable organic/inorganic hybrid nanocomposites with metal alloys and their application for encapsulation of organic solar cells
(2008-11-01)
Chen, Chen-Ming
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Chung, Ming-Hua
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Hsieh, Tsung-Eong
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Liu, Mark O.
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Lin, Jen-Lien
We have successfully prepared ultraviolet (UV) curable organic/inorganic hybrid nanocomposites with good thermal stability, moderate adhesion strength, and excellent barrier capability. In order to improve the gas blocking properties, the metal alloy (Invar) has been blended with lab-made organic/inorganic hybrid nanocomposites, dramatically not only raising the gas resistance but also reducing the shrinkage after UV curing. Moreover, we have also applied lab-made nanocomposite IV for the encapsulation of organic solar cells. The experimental results reveal that introduction of nanocomposite IV can effectively block the penetration of moisture as well as oxygen in the air into the devices and consequently promote the lifetime of organic solar cells. (C) 2008 Elsevier Ltd. All rights reserved.
Ultraviolet-assisted synthesis of encapsulating adhesives and their application for lifetime improvement of organic light emitting diodes
(2009-07-01)
Chen, Chen-Ming
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Chung, Ming-Hua
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Hsieh, Tsung-Eong
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Huang, Bohr-Ran
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Hsieh, Huai-En
The lifetimes of organic light emitting diodes (OLEDs) have been Successfully enhanced with the modulation of LiF thickness mid the utilization of encapsulating adhesives, which have been successfully and synthesized with UV irradiation. Experimental results demonstrate that LiF and lab-made encapsulating adhesives can block the invasion of moisture as well as oxygen in the atmosphere into the OLEDs so that the lifetimes of devices with their encapsulation are 18-folds longer than those without encapsulation. (c) 2008 Elsevier B.V. All rights reserved.