Search

Your search keyword '"Arakawa, Hironori"' showing total 619 results
Start Over Author "Arakawa, Hironori"
619 results on '"Arakawa, Hironori"'

9. Influence of dye adsorption solvent on the performance of a mesoporous Ti[O.sub.2] dye-sensitized solar cell using infrared organic dye

Author

Ono, Takahiko, Yamaguchi, Takeshi, and Arakawa, Hironori

Subjects
Adsorption -- Chemical properties, Titanium dioxide -- Chemical properties, Solar batteries -- Materials, Solar batteries -- Chemical properties, Solar batteries -- Testing, Solar cells -- Materials, Solar cells -- Chemical properties, Solar cells -- Testing, Organic dyes -- Usage, Organic dyes -- Optical properties, Infrared radiation -- Research, Performance-based assessment -- Methods, Performance-based assessment -- Equipment and supplies, Performance-based assessment -- Technology application, Technology application, Engineering and manufacturing industries, Environmental issues
Abstract

The influence of a dye adsorption solvent of an infrared organic dye (NK-6037) on solar cell performance was investigated in a mesoporous Ti[O.sub.2] dye-sensitized solar cell (DSC). Various types of alcohols and a mixture of ethanol and tertiary-butanol (t-butanol) were applied as dye adsorption solvents. It was confirmed that the species of dye adsorption solvent significantly influences the performance of a DSC. Decreasing the specific dielectric constant of the dye adsorption solvent caused the amount of dye adsorbed on the Ti[O.sub.2] photoelectrode to increase dramatically. It is suggested that the specific dielectric constant of the dye adsorption solvent influences the solvation state of the NK-6037 dye in the solvent, thus determining, for instance, whether the dye is in the monomer state or the aggregate state. Interestingly, solar cell performance was not linearly proportional to the adsorbed amount of dye but a precise optimum amount of adsorbed dye was required for the best performance of the DSC. The optimum amount of adsorbed dye was approximately 5.0 x [10.sup.-8] mol/[cm.sup.2] and it was obtained by using solvents having a dielectric constant of approximately 18. This condition was realized by 1-butanol, 2-propanol, and a mixture of ethanol and t-butanol with a volume ratio of 7:3. The best efficiency obtained for the DSC was 1.7%, using the optimum amount of the adsorbed infrared dye NK-6037. It is speculated that an excess of dye on the Ti[O.sub.2] photoelectrode accelerates the formation of H-type dye aggregates, resulting in a decrease in short circuit photocurrent ([J.sub.sc]) by unfavorable side reactions of electron loss. It is demonstrated that dye adsorption solvent selection is the critical factor in obtaining high performance in a DSC [DOI: 10.1115/1.4001171] Keywords: dye-sensitized solar cell, infrared organic dye, dye adsorption solvent

Published
2010

15. Molecular design of coumarin for efficient dye-sensitized solar cells

Author

Hara, Kohjiro, Shinpo, Akira, Suga, Sadaharu, Sato, Tadatake, Sayama, Kazuhiro, Katoh, Ryuzi, Sugihara, Hideki, Furube, Akihiro, Arakawa, Hironori, and Ohga, Yasuyo

Subjects
Crystals -- Properties, Crystals -- Research, Solar batteries -- Research, Solar cells -- Research, Coumarins -- Analysis, Chemicals, plastics and rubber industries
Abstract

The study was done where novel dyes were developed for use in dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) and spectroscopic studies. The study discusses molecular designs of coumarin dyes for efficient dye-sensitized solar cells in detail.

Published
2003

21. Surface characterization of nanoparticles of NiO(sub x)/In(sub 0.9)Ni(sub 0.1)TaO(sub 4): effects on photocataytic activity

Author

Zou, Zhigang, Ye, Jinhua, and Arakawa, Hironori

Subjects
Quantum chemistry -- Analysis, Crystallization -- Methods, Nitrogen oxide -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

A study is conducted to develop the highly crystalline nanoprticles of NiO(sub x)/In(sub 0.9)Ni(sub 0.1)TaO(sub 4), with a wolframite-type structure, with the help of a solid-state reaction method. The TEM measurements indicate that nearly spherical nano NiO(sub x) particles with a size of about 15 nm are distributed on the surface of In(sub 0.9)Ni(sub 0.1)TaO(sub 4) with a quantum yield of about 0.66 percentage.

Published
2002

22. Efficiencies of electron injection from excited sensitizer dyes to nanocrystalline ZnO films as studied by near-IR optical absorption of injected electrons

Author

Katoh, Ryuzi, Furube, Akihiro, Hara, Kohjiro, Murata, Shigeo, Sugihara, Hideki, Arakawa, Hironori, and Tachiya, M.

Subjects
Molecular structure -- Observations, Near infrared spectroscopy -- Observations, Zinc oxide -- Spectra, Zinc oxide -- Atomic properties, Chemicals, plastics and rubber industries
Abstract

Near-IR absorption spectra of electrons injected from excited sensitizer dyes to nanocrystalline ZnO films are studied. The absorption steeply increases with increasing wavelength and can be assigned to the optical transition of conducting electrons to higher energy levels of the conduction band.

Published
2002

24. Photoelectrochemical properties of J aggregates of benzothiazole merocyanine dyes on a nanostructured TiO (sub)2 film

Author

Sayama, Kazuhiro, Tsukagoshi, Shingo, Hara, Kohjiro, Ohga, Yasuyo, Shinpou, Akira, Abe, Yoshimoto, Suga, Sadaharu, and Arakawa, Hironori

Subjects
Chemistry, Physical and theoretical -- Research, Photochemical research -- Analysis, Dyes and dyeing -- Chemistry, Benzene -- Physiological aspects, Titanium -- Physiological aspects, Oxygen -- Physiological aspects, Thin films -- Physiological aspects, Chemicals, plastics and rubber industries
Published
2002

28. Catalysis research of relevance to carbon management: progress, challenges, and opportunities

Author

Arakawa, Hironori, Aresta, Michele, Armor, John N., Barteau, Mark A., Beckman, Eric J., Bell, Alexis T., Bercaw, John E., Creutz, Carol, Dinjus, Eckhard, Dixon, David A., Domen, Kazunari, DuBois, Daniel L., Eckert, Juergen, Fujita, Etsuko, Gibson, Dorothy H., Goddard, William A., Goodmn, D. Wayne, Keller, Jay, Kubas, Gregory J., Kung, Harold H., Lyons, James E., Manzer, Leo E., Marks, Tobin J., Morokuma, Keiji, Nicholas, Kenneth M., periana, Roy, Que, Lawrence, Rostrup-Nielson, Jens, Sachtler, Wolfgang M.H., Schmidt, Lanny D., Sen, Ayusman, Somorjai, Gabor A., Stair, Peter C. Stults, B. Ray, and Tumas, William

Subjects
Catalysis -- Research, Carbon compounds -- Research, Greenhouse effect -- Evaluation, Technological innovations -- Models, Chemical research -- Innovations, Chemistry
Abstract

This review summarizes the deliberations of a workshop colloquium on the 'opportunities for catalysis research in carbon management'. Research progress within the context of greenhouse gas/carbon issues in the areas of hydrogen generation and utilization, carbon dioxide activation, catalysis research to further our search for new and more efficient catalytic processes.

Published
2001

Catalog

Books, media, physical & digital resources
See catalog results