Effect of hydrogen plasma treatment on nano-structured TiO2 films for the enhanced performance of dye-sensitized solar cell

We report an efficient method to improve the efficiency and stability of DSSC with nano-structured TiO2. A low temperature RF plasma-enhanced chemical vapor deposition (PECVD) system was utilized for hydrogen plasma treatment on nano-structured TiO2 film. We confirmed that the efficiency of DSSCs was significantly dependent on the plasma power. This increased the hydrophilic property, the excess electrons and dye adsorption on its surface. The relative change in surface chemistry and hydrophilic characteristics with plasma treatment was investigated using various analysis methods. In our study, we showed that DSSC with plasma-treated TiO2 had a power conversion efficiency of 6.94%, which is 21% higher than that without plasma treatment. It was found that the plasma treatment caused both increased dye adsorption and significant longer electron lifetime.