Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Volume 76 , Issue 2
Showing 1-19 articles out of 19 articles from the selected issue
Photoelectrochemistry: From Nano Materials to Devices
  • Hideki MINOURA, Tsukasa YOSHIDA
    2008 Volume 76 Issue 2 Pages 109-117
    Published: February 05, 2008
    Released: March 22, 2012
    Upon cathodizing a conducting substrate in O2 saturated aqueous mixed solution of ZnCl2 and eosinY,ZnO/eosinY nano-hybrid films with high crystallinity, high transparency and grain boundary-free nano-porous structure are deposited. By soaking the films in soft alkaline solution, eosinY is completely removed without any change in film thickness. By re-loading various dyes onto the surface of these films, highly transparent ZnO films with various colors are easily obtained. The ZnO films thus loaded with various dyes are effectively applied to flexible and colorful dye-sensitized solar cells. Owing to superior properties of the films obtained under optimized conditions, the incident photon to current conversion efficiencies of the solar cells re-loaded with some kinds of organic dyes amount to 90%. Solar-to-electrical energy conversion efficiency of the DSSC employing D149 dye (Mitsubishi Paper Mills Limited) amount to 5.6% under illumination of AM1.5 simulated sun light (100 mW cm−2). Efficient flexible colorful solar cells by using ITO-coated PET film substrates have been fabricated. Novel application of our plastic solar cells such as wearable solar cells and the solar powered functional traffic signs has been proposed.
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  • Kefeng YU, Nobuyuki SAKAI, Tetsu TATSUMA
    2008 Volume 76 Issue 2 Pages 161-164
    Published: February 05, 2008
    Released: March 22, 2012
    Plasmon resonance-based solid-state photovoltaic cells were fabricated with the TiO2 electron transport layer, gold nanoparticles as the visible light sensitizer and an organic or inorganic hole transport layer. The devices showed prompt, reproducible photocurrent and photovoltage responses during periodical visible light illumination. The action spectra for the photocurrent and photovoltage closely matched the absorption spectrum of the gold nanoparticles, indicating that the observed photoresponses arose from light absorption of the gold nanoparticles. The cell performances depended on the hole mobility of the hole transport layer. The largest photocurrent and photovoltage were recorded when CuI was used as the hole transport material.
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  • Osamu KITAO
    2008 Volume 76 Issue 2 Pages 165-170
    Published: February 05, 2008
    Released: March 22, 2012
    The absorption spectra of five β-diketonato ruthenium tricarboxyterpyridyl dyes in ethanol have been calculated by the Time Dependent Density Functional Theory, and studied by the Transition-Component Analysis (TCA). The computed absorption spectra well reproduced the experimental ones based on the shape for the entire visible light range. The TCA quantitatively explained the contents of the absorption spectrum in detail, and, by comparing to the results for Black Dye, found that the β-diketonato ligands, by enhancing the electron donor ability, could contribute to the absorption spectra in the longer wavelength region, and made the β-diketonato ruthenium tricarboxyterpyridyl dyes work well as photo-sensitizers in dye-sensitized solar cells.
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  • Hiroshi IRIE, Ken OBATA, Tatsuo SHIBATA, Kazuhito HASHIMOTO
    2008 Volume 76 Issue 2 Pages 171-174
    Published: February 05, 2008
    Released: March 22, 2012
    Photoelectrochemical etching was applied to (0001), (000-1), and (10-10) surfaces of ZnO single crystals to produce unique surface structures, which depend on the crystallographic face. These surfaces turned hydrophilic with a water contact angle of 5–10° under ultraviolet light irradiation, but the hydrophilicity gradually became small in the dark. Among them, we successfully generated a hydrophobic surface (contact angle >120°) stored in a dark under ambient conditions on the etched (000-1) face with hexagonal holes that had a diameter of approximately 100 nm along the c-axis. In addition, storing at 75°C in a dry oven greatly shortened the period of the hydrophobic conversion.
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