Correlation between Conversion Efficiency and Impedance Spectroscopy Parameters for Dye Sensitized Solar Cell with TiO₂ Nanostructure Modification

Abstract:

Impedance spectroscopy (IS) is a useful technique to investigate the detail of charge transfer in dye sensitized solar cell (DSSC) especially for individual part of cell component. The charge transport in electrolyte, platinum and TiO₂ electrodes can be separately examined by varying the frequency range of IS. In this work, the TiO₂ electrode was modified by various nanostructures and the equivalence circuit parameters extracted from the measured IS were correlated to the power conversion efficiency of fabricated solar cells, in order to describe the origin of decreasing and increasing of the DSSC efficiency. The TiO₂ electrode was prepared at different conditions of mixing with inorganic nanoparticle of CdS, CdSe and nanostructure of C₆₀ at various concentration. Normally, the DSSC with unmodified TiO₂ electrode shows the efficiency about 7.12% at AM 1.5. The dramatically dropping of efficiency was occurred in the cell with very small amount of nanoparticle added in TiO₂ electrode. For most of the cases, the efficiency tended to become increase as increasing the amount of nanoparticle in the TiO₂ electrode. In some structures, the efficiency can become higher than that of the unmodified TiO₂ cell. However the large amount of nanoparticle in TiO₂ electrode leaded to decreasing of cell efficiency in all fabricated types of TiO₂ nanostructure. These efficiency variations were related to the resistance and capacitance values extracted from IS measurement in the frequency range of TiO₂ response. It was found that the extracted value of cell resistance played the important role on the efficiency variation and the capacitance value can be used to describe the life-time of charge carrier in the cells.Keywords: Impedance spectroscopy, dye sensitized solar cell.

• Periodical: Advanced Materials Research (Volume 1131)
• Pages: 169-174
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1131.169
• Online since: December 2015
• Authors: Prathan Prachopchok*, Chanchana Thanachayanon, Tanakorn Osotchan
• Keywords: Dye Sensitized Solar Cell, Impedance Spectroscopy

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