Modification of Solvolytic Sol-Gel Synthesis for Low Temperature TiO2 DSSC Photoelectrode

Solvolytic sol-gel synthesis was applied for the low temperature production of photoelectrode for dye-sensitized solar cell (DSSC). In this study, commercial TiO2 standard (Degussa P25) was used as the main component in the preparation of photoelectrode film. Addition of TiO2 gel prepared from a solvolytic sol-gel method reduced cracking in the dry film while still maintains porosity. Further modification by simply adding hydrofluoric acid (HF) and ammonia (NH3) increase porosity and improve interconnection between fluorine doped tin oxide (FTO) layer on the substrate and the coated TiO2 layer even under low temperature baking condition (<150°C). The modified TiO2 electrode showed significantly better electrical and electrochemical properties. Furthermore, the DSSC cell with modified TiO2 film also showed higher cell efficiency when compared with the controlled cell that used only Degussa P25.