Modification of Electrodes and Electrolytes to Improve Performance of Dye‐Sensitized Solar Cells Using Carbon Nanotube Composite Papers

This study focused on improving the performance of dye‐sensitized solar cells (DSSCs) using carbon nanotube (CNT) composite papers, i.e., paper‐DSSCs. Specifically, poly (3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), a conductive polymer, was introduced into metallic‐CNT composite paper as the anode, and titanium dioxide into semiconducting‐CNT composite paper as the cathode, to improve the performance of paper‐DSSCs. These efforts were aimed at reducing the internal resistance on the anode side and improving the charge collection efficiency generated by light absorption on the cathode side. The relationship between the composition of polyethylene glycol (PEG) and polyvinylidene fluoride (PVDF) in gel electrolytes and the resulting power conversion efficiency (PCE) was also investigated. It was confirmed that the introduction of PEDOT:PSS into the anode resulted in a decrease in internal resistance, while the introduction of titanium dioxide as the cathode contributed to an increase in PCE. Compared to our previous study, this work introduces a modified device structure and newly optimized materials, and all performance data were obtained from new experiments. In addition, a PEG:PVDF composition ratio of 4:6 achieved a higher PCE. Compared to our previous study, the PCE of our new paper‐DSSCs improved to 27.514 × 10 −3 % (approximately 14 times that of the previous study), and the fill factor improved to 0.318 (approximately double). These results demonstrate the validity of our strategy and provide new insights for enhancing the practical viability of paper‐DSSCs. Therefore, the validity of this improvement approach was confirmed and expected to help in the future practical application of paper‐DSSCs.