||Study on Enhanced Photocurrent Properties at Dye/Gold Nanoparticles loaded TiO_2 Thin Films on Metallic Gratings
119 , 2015-03-23 , 新潟大学
学位の種類: 博士（工学）. 報告番号: 甲第4047号. 学位記番号: 新大院博（工）甲第429号. 学位授与年月日: 平成27年3月23日
Dye-sensitized solar cells (DSSCs) are attractive organic-based solar cells on account of their high efficiency and low cost. Many studies on DSSCs have been reported. In this research, DSSC was improved by using an effect of Au-loaded titanium dioxide (Au-loaded TiO_2). The Au-loaded TiO_2 nanopowders were synthesized by the modified sol–gel method together with the impregnation method. Anatase phase of TiO_2 was obtained in all samples with an average particle size of 20 nm. For the enhancement of DSSCs study, DSSCs composed of the Au grating/Au-loaded TiO_2/TMPyP-SCC LbL (20 bilayers)/ electrolyte/ITO substrates were fabricated. Au-loaded TiO_2 films were deposited by electrophoretic deposition. TMPyP and SCC were used as photo-absorbing dyes and were prepared by LbL deposition. The fabricated cells were irradiated with visible light at various incident angles with SP excitation (p-pol.) and without surface plasmon excitation (s-pol.). The results showed that up to a 7.5-fold increase in the short-circuit photocurrent can be obtained by combining Au-loaded TiO_2 with grating-coupled surface plasmon excitation in the cells. For further application on solid-state dye-sensitized solar cell (ss-DSSCs), the fabrication of a grating structure formed by a solid-state electrolyte layer on a dye-TiO_2 film by the nanoimprinting technique using a polydimethylsiloxane (PDMS) stamp and its application in photoelectric conversion devices are described. The PDMS grating pattern was imprinted from blu-ray disc recordable. A silver electrode was deposited on the patterned solid-state electrolyte layers. Surface plasmon resonance (SPR) excitation was observed in the fabricated solar cells by irradiation with white light. The photoelectric conversion properties were measured to study the effect of the two types of SPR excitations, i.e., the propagating surface plasmon on the Ag grating surface and the localized surface plasmon from the Au nanoparticles on TiO_2.