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Accession number;07A0043212
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| Title;PHOTOTHERMAL CHARACTERIZATION OF CDSE QUANTUM DOTS ADSORBED ON NANOTUBE TIO2 ELECTRODES |
| Author;
TOYODA TARO
(Univ. of Electro-Communications)
TAMURA SATORU
(Univ. of Electro-Communications)
YAMAMOTO KANA
(Univ. of Electro-Communications)
SHEN QING
(Univ. of Electro-Communications)
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Journal Title;Thermophys Prop
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Journal Code:X0031A
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ISSN:0911-1743
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VOL.27th;NO.;PAGE.30-32(2006)
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| Figure&Table&Reference;FIG.6, REF.8 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;Morphologies of titanium dioxide (TiO2) electrodes and the choice of sensitizers have been important factors for the improvement of energy conversion efficiency for dye-sensitized solar cell (DSSC). TiO2 electrodes, having a higher degree of order than random assemblies of nanoparticles, are desirable for the improvement of the electron transport characteristics. In recent years, semiconductor quantum dots (QDs) have attracted much attention as sensitizers, replacing organic dyes in DSSCs. In this study, TiO2 electrodes, composed of nanotubes and nanowires, were prepared from TiO2 gels using a surfactant-assisted self-assembling method. Since use of semiconductor QDs as sensitizers has some advantages in solar cell applications, CdSe QDs were adsorbed onto TiO2 electrodes as sensitizer using chemical deposition technique. We investigate the effect of adsorption time and temperature (as adsorption parameters) on crystal growth of CdSe QDs using optical absorption spectroscopy. The optical absorption of CdSe QDs was measured by using photoacoustic (PA) technique. PA technique is a photothermal (PT) method which is useful for optical opaque or scattering materials such as nanostructured TiO2 electrodes. We can evaluate the average diameters of CdSe QDs made of different adsorption times and temperatures from the blueshift part of the PA spectra relative to bulk CdSe with the help of the effective mass approximation. Adsorption time (t) dependence of diameter for CdSe QDs in fixed temperature consists of two terms, proportional to t and t'1/3'. The first term in time dependence of CdSe QDs crystal growing reflects suppress effect and the second for normal volume growing. Coefficients of both terms depend on temperature and concentration of chemical deposition. (author abst.) |
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