| 초록 |
We studied a replacement of I-/I3- couple system that has problems such as the corrosion of electrode materials, partial absorbance of visible light and the loss of energy between its redox potential and that of the conventional sensitizers. Recently Grtzel et al. has shown that 2,2,6,6-tetramethyl-1-piperidinyloxy(TEMPO) is a potential candidate for the redox couple. In order to design a new redox couple for the stable DSSC, we checked six cyclic nitroxyl free radicals having different substitution groups. Among them, we observed that 4-hydroxy-TEMPO has a suitable redox potential range and also that there was an increase of more about 120mV in Voc when using 4-hydroxy-TEMPO redox couple system than I-/I3- redox couple system, although the device using 4-hydroxy-TEMPO has low fill factor. And both photovoltaic performance and EIS showed that 4-hydroxy-TEMPO/4-hydroxy-TEMPO+ is suitable as redox system in DSSC. We tried to improve the fill factor of this redox system using adsorbent. |
