When the size of display panel increased, the RC delay of TFTs became serious. High dielectric (high-k) materials used as the gate oxide can increase the gate oxide capacitance Co, which can induce a higher drain current, and higher aperture ratio. Therefore, low-k materials are used for inter-metal dielectrics. Thus, it can improve the RC delay. LPD-TiO2 film on a-Si and poly-Si technology and characterization of films were described in detail in this thesis. The highest dielectric constant of 11.76 and 29.54, and lowest leakage current density of 5.45¡Ñ10-7A/cm2 at -0.45 MV/cm and 3.11¡Ñ10-1 A/cm2 at 0.45 MV/cm for the O2-annealed of LPD-TiO2film on a-Si and poly-Si can be obtained.

In this thesis, we present a new Poly - Si TFT process method to overcome Self - heating effect and Floating body effect. The main drawback of a conventional Poly - Si TFT is the existence of self - heating effect and floating body effect. The self - heating effect leads to drain current reduced and the floating body effect leads to premature device breakdown and kink effects. Here, we utilize all kinds of different isolation technologies to form non - continuing buried layer. Between the non - continuing buried layer there are pass ways, which contact the active region and the substrate directly. Because of conventional LOCOS isolation technology has longer bird¡¦s beak, the familiar method of SILO and PBL isolation technologies are used to reduce bird¡¦s beak. Also, we use STI isolation technology to build up non - continuing buried layer, which can control the width of pass way more easily. It is proved from the measurement that the pass way can slow down the self - heating effect and the floating body effect successfully.

With the rapid emergence and proliferation of Internet and the trend of globalization, a tremendous number of textual documents written in different languages are electronically accessible online. Efficiently and effectively managing these textual documents written different languages is essential to organizations and individuals. Although poly-lingual text categorization (PLTC) can be approached as a set of independent monolingual classifiers, this naïve approach employs only the training documents of the same language to construct to construct a monolingual classifier and fails to utilize the opportunity offered by poly-lingual training documents. Motivated by the significance of and need for such a poly-lingual text categorization technique, we propose a PLTC technique that takes into account all training documents of all languages when constructing a monolingual classifier for a specific language. Using the independent monolingual text categorization (MnTC) technique as our performance benchmark, our empirical evaluation results show that our proposed PLTC technique achieves higher classification accuracy than the benchmark technique does in both English and Chinese corpora. In addition, our empirical results also suggest the robustness of the proposed PLTC technique with respect to the range of training sizes investigated.

Polyaniline (PAn) is an important conjugated conducting polymer because of its good environmental stability. However, the conductive form of polyanilune is difficult to processed because it is insoluble in common organic solvent. This property limits its processibility and application. In the study, we developed a feasible route for preparing polyaniline/surfactant core-shell latex to solve the insoluble problem. The polyaniline latex was made by emulsion polymerization of aniline monomer, using ionic polymer (poly(4-vinylpyridine)-methanesulfonic acid; P4VP(MSA)) as the surfactant and dopant. And then, the nano-size and core-shell morphologies of polyaniline latex was studied by Transmission electron microscopy (TEM) technique. The best conductivity of polyaniline film is approach to 10-2 S/cm.

Surface Laser Light Scattering (SLLS) is a heterodyne detection technique used to probe the surface properties of fluid interfaces. These interfaces are either liquid/liquid or vapor/liquid, and they may include insoluble monolayers or polymer films deposited on liquid surfaces as well as microemulsions in solution at low concentration. This technique provides one with a nonperturbative way to obtain surface tension and viscosity. A diffraction grating is employed to provide a stable local oscillatior, hence selecting an accurate ripplon wave vector . This thesis deals with the investigation of the interface between air and solution consisting of the methanol and water mixture and poly(N-isopropylacrylamide) or PNIPAM which is one of the fascinating polymeric materials. The polymer PNIPAM shows distinct responses to variations in the surrounding environment (such as thermal gradient, change in pH, etc.). The surface tension extracted from the SLLS data using the Kelvin equation is found to agree well with that obtained by using the Wilhelmy plate method. For the range of wave vectors cm-1, the power spectrum detected in frequency domain can be fit to a Lorentzian profile. Our experiments show that when the volume percentage of methanol increases, the interfacial property becomes insensitive to the presence of PNIPAM.

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Monomer 4,4¡¦¡¦¡¦¡¦-Difluore-3,3¡¦¡¦¡¦¡¦-bis(trifluoromethyl)-2¡¦¡¦,3¡¦¡¦,5¡¦¡¦,6¡¦¡¦-triphenyl (M4) were converted to novel poly(arylene ether)s by nucleophilic displacement reaction with several bisphenols in this study, then we called them : P-A1, P-A2, P-B1, P-B2. These polymers exhibit weightaverage molecular weight (Mw) between 2.2¡Ñ10^4 to 2.2¡Ñ10^5 g/mol. The molecular weight were investigated and confirmed by Mass and GPC. The molecular structures were investigated and confirmed by NMR and FT-IR.Thermal analysis physics studies with these polymers confirmed by Thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC). It is indicated that Td 5% of these polymers were 450¢XC ~ 548¢XC in TGA and Tg of these polymers were 303¢XC ~ 324¢XC in DSC.Besides, these polymers not were observed apparent crystallizing point, so we consider that they are not easy crystallized. Therefore, they could make manufacture in higher temperature and have higher thermal stability.In photophysical property of polymeric thin films, we obtained absorption wavelength that was 232nm ~ 300nm in UV-Vis absorption spectra and excitation wavelength that was 362nm ~ 368nm in PL spectra. Furthermore, the transmission spectra of polymeric thin films showed that visible light transparency were up to 83%. Besides, we used Ellipsometer to measure refractive index(n) that is 1.33 ~ 1.49.In drop shape analysis system, contact angles of the polymeric thin films are more than 109.8¢X. They show that the polymer thin films have low polarity and good hydrophobicity. By above material properties of these polymers, they have high thermal stabilities, high optical transparency, low polarity and good hydrophobicity. These good material properties are doing as a plastic substrate of devices or panel display.

P3DDT (3-dodecylthiophene-2,5-diyl) and PCBM( [6,6]-phenyl C61-butyric acid methyl ester) were fabricated to the active layer of Bulk Heterojunction Organic Solar Cells .We obtained the device efficiency was 0.64 % by evaporating solvent at room temperature. We measured Thermal decomposition Temperature (Td) of P3DDT was 487¢J. But operational temperature was over 90¢J, it could affect the roughness of thin film and make efficiency to be 4¡Ñ10-3(%). For results of experiments, we know that roughness changed by the crystallization of side chain and exciton dissociation modified by the morphology between P3DDT and PCBM. Thin film solar cell has a large effect on the formation of active layer, such as heat treatment, choices of solvents, composition ratio, and speed of spin coating. The efficiency of solar cell has been shown to be highly sensitive to the size, composition and crystallization of the formed domains. We studied two kinds of conjugated polythiophenes with the same main chain but different side chain. When the number of carbon atoms of alkyl side chains is more than 10, some orderly arrangements will occur for side chains between the layers. We tried to explain the crystallization caused by long alkyl side chains determined which intrinsic phenomena are the most evident for altering the PCE of solar cell. After recrystallization, the layered structures of P3DDT can be improved, but those orderly degrees of the arrangements with PCBM are further aggregated. The main point for low PEC and Jsc by heat treatment is the unfavorable and roughened morphology. Charge transfer only occurs at the boundary ,which is interfacial area between donor and acceptor materials, hence, the low Jsc could be caused by poor charge transfer between P3DDT and PCBM. The redistributed arrangement of P3DDT domains exclude PCBM from original space, and it makes PCBM to aggregate large particles, from nanophase to mesophase scales, which reduce mutual solubility to be the source of PCE and Jsc reduction.

The effect of antiplasticization on barrier properties of poly(ethylene terephthalate) (PET) has been investigated through transport measurements and some supplementary characterization techniques including dynamic mechanical measurements and solid state 13C cross polarization/magic angle spinning (CP/MAS) NMR. Our oxygen and carbon dioxide transport results were well described by a combination of the free volume based interpretation and interaction energy estimation. Transport characterization and DSC techniques verified that there exists a third element, a de-densified amorphous fraction in crystallized PET. Both oxygen and carbon dioxide permeabilities at 1 atm at 35ºC in PET with different crystallinities were well described by the Nielsen model due to the presence of an adjustable parameter, Ar, even though it is based on a two phase model. The comparison of the barrier improvement factor (BIF) values for samples annealed at 100ºC demonstrated that a combination of antiplasticization and crystallization allows for very efficient chain packing, which significantly improves the barrier properties of PET. A thorough molecular level study using dynamic mechanical analysis supported the synergistic effect of antiplasticization and crystallization on the molecular motion in PET. Lastly, a vapor/gas permeation system with a new concept of a flexible humidity and methanol vapor partial pressure clamp was designed and constructed. Even though its permeation results are not available at this point, its operational feasibility was well verified by pre-calculations and physical explanations. This system may be used for future studies to evaluate barrier properties of PET or modified PET samples.

Diese Arbeit liefert die Grundlage für intelligente Beschichtungen aus kovalent gebundenen Polymeren, sogenannten Polymerbürsten, mit Schichtdicken von wenigen Nanometern. Durch ihre Fähigkeit die Oberflächeneigenschaften je nach Umgebungstemperatur, pH Wert und Zusammensetzung zu ändern, kann die Adsorption von Biomolekülen auf eine einzigartige Art und Weise kontrolliert und reguliert werden. Die zusätzliche Modifizierung der Polymerbürsten mit Elektronenstrahlen ermöglicht die Generierung von Gradienten und erweitert die Anwendungsmöglichkeiten in vielfältigen Bereichen der interdisziplinären Forschung, wie z.B. in Hinblick auf das Lab-on-Chip Design oder die Biomedizin. / Polymer brushes represent sensitive coatings with thicknesses of few nanometres and are interesting for interdisciplinary scientific research, e.g. for intelligent lab-on-chip design or biotechnology. It is demonstrated in this work, that polymer brushes are able to change their surface properties depending on the ambient conditions like solvent quality, temperature or pH value. This sensitivity highly influenced the adsorption of bio molecules. Especially mixed polymer brushes enabled the tuning of the adsorbed amount of various proteins and cells. To create surface gradients or structures in the different polymer brush surfaces, controlled electron beam modification was applied.