ELECTROSPUN POLYMER-FIBER SOLAR CELL

A study of fabricating the first electrospun polymer-fiber solar cell with MEHPPV is presented. Motivation for the work and a brief history of solar cell is given. Limiting factors to improvement of polymer solar cell efficiency are illustrated. Electrospinning is introduced as a technique that may increase polymer solar cell efficiency, and a list of advantages in the technique applied to solar cell is discussed. Results of electrospun polymer-fiber solar cell, absorption, and its device parameter diagnosis through an equivalent circuit analysis are presented

Raman Scattering in GaN and ZnO

The Micro-Raman scattering technique has been used for the study of GaN and ZnO. Capabilities of the Raman technique and existing literature on Raman spectroscopy in GaN and ZnO are reviewed. About 50 GaN and ZnO samples with a wide range of properties are studied. From the analysis of positions of the E2H and A1(LO) phonon modes, biaxial stress and plasmon coupling of the Al(LO) mode are observed and compared to a bulk GaN sample. The stress-related shift rate for the AI(LO) mode in hexagonal GaN is established to be 2.7 ± 0.4 cm-1/GPa through series of GaN with low free carrier concentration. Bulk ZnO and ZnO layers grown on sapphire have been studied, and no biaxial stress is found in ZnO layers. Doping and impurity modes resulted in disorder-activated scattering in ZnO. The choice of the laser for study of GaN and ZnO layers on sapphire substrate is discussed

Electrokinetic separation of co-solutes into bimodal fibers by electrospinning

Composite and chemically/physically distinct fibers of sodium poly[2-(3-thienyl)-ethoxy-4-butylsulfonate] (PTEBS) and polyethylene oxide (PEO) were formed by electrospinning from a homogeneous aqueous solution containing PTEBS and PEO co-solutes. Composite nanofibers of diameter of ∼60nm were electrospun from an aqueous solution. The addition of ammonium hydroxide (NH4OH) to the water solution resulted in “bimodal” electrospun fibers consisting of distinct large diameter white PEO fiber segments and small diameter black PTEBS fiber segments. The optical absorptionspectrum of the composite PTEBS/PEO nanofibers did not exhibit the characteristic peak around 460nm, which is present in the bulk spectrum

Electrospun Polymer-Fiber Solar Cell

A novel electrospun polymer-fiber solar cell was synthesized by electrospinning a 1 : 2.5 weight% ratio mixture of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) resulting in bulk heterojunctions. Electrospinning is introduced as a technique that may increase polymer solar cell efficiency, and a list of advantages of the technique applied to solar cells is discussed. The device achieved a power conversion efficiency of η = 3.08 x 10-7%. The absorption and photoluminescence of MEH-PPV nanofibers are compared to thin films of the same material. Electrospun nanofibers are discussed as a favorable structure for application in polymer solar cells

Electrospun Polymer-Fiber Solar Cell

A novel electrospun polymer-fiber solar cell was synthesized by electrospinning a 1 : 2.5 weight% ratio mixture of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) resulting in bulk heterojunctions. Electrospinning is introduced as a technique that may increase polymer solar cell efficiency, and a list of advantages of the technique applied to solar cells is discussed. The device achieved a power conversion efficiency of %. The absorption and photoluminescence of MEH-PPV nanofibers are compared to thin films of the same material. Electrospun nanofibers are discussed as a favorable structure for application in polymer solar cells

F-molding: A New Production Method for Largely Aspherical Mirrors of Cordierite

Cordierite is a rigid low thermal expansion coefficient ceramic equivalent to that of low thermal expansion glass but with voids due to forming with raw material powder. To overcome this problem, we propose Flexible Molding (F-molding) as our new fabrication method. With F-molding, the raw material powder is converted to liquid slurry, which is poured into a resin mold, solidified, and directly formed into near net design of a mirror. The mold prepared from F-molding is an effective tool for processing multiple volumes of identical structures such as those used in segmented mirror designs. We introduce details of our fabrication method in F-molding mirror and report its measurement results of optical performances with a 270mm diameter sample

原子核の変形と核力, 1

京都大学0048新制・課程博士理学博士理博第22号新制||理||10(附属図書館)133京都大学大学院理学研究科物理学専攻(主査)教授 小林 稔, 教授 湯川 秀樹, 教授 林 忠四郎学位規則第5条第1項該当Kyoto UniversityDA

Vanadium-catalyzed enantioselective Friedel–Crafts-type reactions

Vanadium-mediated enantioselective Friedel–Crafts (FC)-type reactions were established using the dinuclear vanadium complex (Ra,S,S)-1a. The vanadium complex promoted the FC-type reaction of imines with 2-naphthols or indoles to give corresponding adducts with high enantioselectivities

The Mechanism of Melanocytes-Specific Cytotoxicity Induced by Phenol Compounds Having a Prooxidant Effect, relating to the Appearance of Leukoderma

Specific phenol compounds including rhododendrol (RD), a skin-brightening ingredient in cosmetics, are reported to induce leukoderma, inducing a social problem, and the elucidation of mechanism of leukoderma is strongly demanded. This study investigated the relationship among the cytotoxicities of six phenol compounds on B16F10 melanoma cells and HaCaT keratinocytes and generated reactive oxygen species (ROS). As a result, the cytotoxicity of RD on B16F10 cells was higher than that on HaCaT cells, and RD significantly increased intracellular ROS and hydrogen peroxide (H2O2) levels in B16F10 cells. Furthermore, although raspberry ketone (RK), RD derivative, also increased intracellular ROS in B16F10 cells, increase in ROS was suppressed by disodium dihydrogen ethylenediaminetetraacetate dehydrate (EDTA). The amounts of increased ROS with RK in HaCaT cells without melanocyte were further increased by tyrosinase. Therefore, tyrosinase, a metalloprotein having copper, was speculated to be one of causative agents allowing phenol compounds to work as a prooxidant. Hydroxyl radical was generated by adding a mixture of tyrosinase and H2O2 to RD, and the amount of the radical was further increased by UVB, indicating that RD cytotoxicity was caused by intracellularly increased ROS, which possibly related to phenol induced prooxidants