2006 Fiscal Year Final Research Report Summary
Preparation of Semiconductor Nanoparticle-Assembled Layers Having Desired Photoluminescent Properties
| Project/Area Number |
16350095
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional materials/Devices
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| Research Institution | Nagoya University (2005-2006)
Hokkaido University (2004) |
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Principal Investigator |
TORIMOTO Tsukasa Nagoya University, Graduate School of Engineering, Professor, 大学院工学研究科, 教授 (60271029)
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| Co-Investigator(Kenkyū-buntansha) |
OHTANI Bunsho Hokkaido University, Catalysis Research Center, Professor, 触媒化学研究センター, 教授 (80176924)
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| Project Period (FY) |
2004 – 2006
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| Keywords | semiconductor nanoparticle / core-shell structure / photoluminescence / jingle-bell shaped structure / photocatalyst / photoetching / recording material / chemical sensor |
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| Research Abstract |
We developed novel strategies of the preparation of silica-coated semiconductor nanoparticle composites which exhibited the desired photochemical properties. The particulate layers of the nanocomposites could be prepared by using layer-by-layer accumulation techniques. The nanostructure of the obtained particles was modified to the shape of the jingle bell by using the size-selective photoetching technique.
First, the size-selective photoetching was applied to silica-coated cadmium selenide (SiO2/CdSe) nanoparticles to precisely control their photoluminescence properties. Although as-prepared SiO2/CdSe did not exhibit photoluminescence, the application of size-selective photoetching to SiO2/CdSe resulted in the development of the band gap emission, the degree being enhanced with progress of the photoetching. Partial photoetching of SiO2/CdSe nanoparticle films produced intense band gap emission of CdSe at the photoetched area, while the remainder of the SiO2/CdSe films did not exhibit d
… More
etectable photoluminescence, resulting in the formation of a clear photoluminescence image under UV irradiation. This technique makes it possible to produce a multicolor photoluminescence image by irradiation with monochromatic lights having various wavelengths using a single source material. Second, the photoluminescence of the jingle-bell-shaped silica-coated cadmium sulfide nanoparticles (SiO2/CdS) was quenched by the addition of trialkylamines, the degree being dependent on their molecular size. These facts were attributable to the molecular-size-selective penetration of quencher molecules from the bulk solution to the void space through the pores of the SiO2 shell of the jingle-bell-shaped nanoparticles.
The prepared jingle-bell-shaped semiconductor nanoparticles seemed to be promising materials for light energy conversion owing to the less amount of recombination sites in the particles, because these exhibited the strong photoluminescence. The jingle-bell-shaped SiO2/CdS particles exhibited much higher photocatalytic activities than those of commercially available bulk CdS particles. For the photoreduction of nitrobenzene, especially, the yield and selectivity of the reduction products could be varied by changing the nanostructure of photocatalysts used. Less
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Research Products
(20 results)
