A Potential of Large Scale of Dye Sensitized Solar Cells using Metallic Titanium Sheet as the Substrate for Photoelectro
- PDF / 137,371 Bytes
- 7 Pages / 612 x 792 pts (letter) Page_size
- 58 Downloads / 144 Views
1013-Z06-06
A Potential of Large Scale of Dye Sensitized Solar Cells using Metallic Titanium Sheet as the Substrate for Photoelectrode Kinji Onoda, Supachai Ngamsinlapasathian, Takuya Fujieda, and Susumu Yoshikawa Kyoto University, Uji, Kyoto, 611-0011, Japan
ABSTRACT The photovoltaic properties of dye-sensitized solar cells (DSCs) based on fluorine doped tin oxide (FTO) and Ti substrates were investigated. The sheet resistances of the substrates were correlated to the photovoltaic properties. The efficiency of the Ti substrate based DSC was higher than that of the FTO substrate based DSC, due to a high fill factor (FF). To minimize the internal resistance of the DSCs, Ti plate was used as a support for nanocrystalline TiO2, because of its low sheet resistance. As the light was absorbed by the electrolyte layer, the incident photon to current efficiency (IPCE) values decreased in the range between 400-600 nm. The electrolyte concentrations were optimized to obtain a higher cell performance. When using an electrolyte composed of 0.02 M I2, 0.2 M LiI, and 0.5 M 4-tert-butylpyridine, an efficiency of 4.98% was obtained for the Ti substrate based DSC with a short circuit current density (Jsc) of 11.25 mAcm2 , an open circuit voltage (Voc) of 0.692 V, and a FF of 0.639. The effect of the cell size on the photovoltaic properties was also investigated. The rate of decrease in a FF and efficiency with increase in the cell size was lower for the Ti substrate based DSCs than the FTO substrate based DSCs. This result indicates that Ti plate is a potential candidate for production of large DSCs. INTRODUCTION Dye-sensitized solar cells (DSCs) have received much attention because of their low production cost and simple manufacturing process, since Gr‰tzel et al. developed a high efficiency DSC [1]. A typical DSC is composed of a transparent conductive glass covered with nanocrystalline TiO2, dye molecules attached to the surface of TiO2, a redox couple electrolyte such as iodide/triiodide, and a counter electrode such as a Pt deposited transparent conductive glass. The n-type semiconductors, such as indium tin oxide (ITO) and fluorine doped tin oxide (FTO), are widely used as transparent conductive glasses. The transparent conductive glass is generally required to have low electrical resistance and high transparency. For the fabrication of DSCs, the transparent conductive glass is usually coated with nanocrystalline TiO2 particles and then sintered at 450-500oC in order to improve the electronic contact, not only between the particles and substrate, but also between the particles [2]. However, the conductivity of conductive glasses decreases when it is sintered at high temperature. Although FTO is generally used as the substrate in DSCs, it has relatively high sheet resistance (10-15 Ω/), and is physically fragile, which are obstacles to increasing the active cell area for the production of large FTO substrate based DSCs. Lowering the sheet resistance of the substrate is a key point for improvement of the performance of large
Data Loading...
