염료감응태양전지의 광전극 표면개질에 의한 고속 염료흡착 특성 연구

Abstract

Since first reported in 1991, dye-sensitized solar cells (DSSCs) have attracted lots of attention due to their high conversion efficiency over 12%, and low fabrication cost. However, for the commercialization, the productivity which is related with the fabrication time should be further enhanced. Among each step for the fabrication of DSSCs, the dye adsorption takes longest time, therefore, the reducing dye adsorption time is the key factor to improve the productivity. It has been known that the conventional dye, that is, N719 is adsorbed onto the TiO2 photoanode in DSSCs by the esterification reaction between the carboxylate groups of N719 and the TiO2. In this study, the temperature, the concentration of dye solution, and the surface chemical state of TiO2 photoanode were varied, and their effects on the dye adsorption time, reaction kinetics of dye adsorption were characterized. In particular, the surface of TiO2 photoanode was modified with nitric acid (HNO3) treatment. Furthermore, the effects on the photovoltaic properties of DSSCs were also examined. The reaction kinetics of dye adsorption according to the adsorption condition was quantitatively compared by the pseudo-first-order reaction model. In addition, the modified surface of TiO2 was characterized by using ATR-FTIR, Raman spectra, which confirmed that there was no difference between the photoanode without nitric acid treatment (w/o HNO3) and with nitric acid treatment (w HNO3). As a result, the dye adsorption time was reduced to 20 minutes by the optimized adsorption condition, which is about 17.5 times faster adsorption time compared to the conventional process. In addition, it was confirmed that the DSSC prepared through the rapid dye adsorption has the comparable conversion efficiency and stability compared those through the conventional process.