Dye-sensitized solar cell performance using microporous ceramic membranes as electrolyte framework support

• Main Authors: Hseng Shao Chen, 陳昇卲
• Other Authors: S. J. Lue
• Format: Others
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/15099854144393671084

碩士 === 長庚大學 === 化工與材料工程學系 === 98 === This study investigates the effect of adding Al2O3 microporous ceramic membranes in dye sensitized solar cells (DSSC) on the DSSC electrochemical performance. We used field emission scanning electron microscope (FE-SEM) to characterize the ceramic membranes, and observed that they have different surface morphologies on both sides, high porosity, and cylindrical pore structure characteristics. Electrochemical impedance analysis revealed that the conductivity of the electrolyte impregnated ceramic membranes were decreased (9.39-6.24 mS/cm) compared with the liquid electrolyte (25 mS/cm). The diffusion coefficient of tri-iodide ions were slowed down by the ceramic membranes in symmetric cells. The exchange current density at Pt-electrolyte interface were decreased with the membrane of the Al2O3 ceramic membranes porosity (11.42-11.02 mA/cm2 compared with 11.53 mA/cm2). From evaporation test on symmetric cells, we found that the microporous characteristics of ceramic membranes could lessen the evaporation rate of the electrolyte solvent. The light-to-electrical energy conversion efficiency of the DSSC reduced with membrane porosity. The efficiency of DSSC containing 0.2, 0.1 and 0.02 μm were 6.67 %, 6.46 % and 6.01 %, respectively. This reduction was associated with the diffusion coefficient of tri-iodide and the exchange current density at Pt-electrolyte interface decreases. After aged for 240 hours of alternative of light and dark cycles, the recession rate of cell efficiency with Al2O3 ceramic membranes was smaller than the control cells. Incorporation of ceramic membranes in DSSC can prevent electrolyte solvent evaporation, and enhance the cell lifes in usage.