ELECTRICAL CONDUCTIVITIES, PLASMONIC PROPERTIES AND VIS-RESPONSIVE ACTIVITIES OF Ag-NANOPARTICLES/TITANIA COMPOSITE THIN FILMS FABRICATED USING MOLECULAR PRECURSOR METHOD (MPM)

摘要

本論文は，化学的湿式法の分子プレカーサー法(MPM)により，前例のない広範囲な濃度の銀ナノ粒子をチタニアに均一分散した銀ナノ粒子/チタニア（Ag-NP/TiO_2)複合薄膜についての研究を，全10章にまとめたものである.%The fabncation of Ag-NP/TiO_2 composite nanostructured thin films, enhancement of its electrical conductivity, and their potential applications due to the visible -light - driven plasmon, where by large amounts nano-scale Ag particles up to 80 mol% can be incorporated in titania matrix using a chemical processes, are the main subjects studied in this thesis. Titanium dioxide (titania or TiO_2) as a semiconductor displays photo - responsive behavior under ultraviolet (UV) light irradiation, thereby severely limiting its practical applications. It is highly desirable to develop a new visible-light-driven TiO_2 based thin film that can use visible light under sunlight irradiation. In another scientific field, it is well understood that the excitation of localized plasmon on the surface of silver-nanoparticles (Ag-NP) causes a tremendous shifting of plasmon resonance peak at well-defined wavelengths near UV and in the visible region. Moreover, incorporating more amount of nano-scaled size Ag particle is necessary for decreasing of the electrical resistance of TiO_2 from 10~(12)Ω.