Carbon nanotubes on fluorine-doped tin oxide for fabrication of dye-sensitized solar cells at low temperature condition.

The multi-walled carbon nanotubes (MWCNTs), electrophoretically deposited on fluorine-doped tin oxide (FTO), were employed as charge-collecting channels in the TiO2 photoelectrode of dye-sensitized solar cells (DSSCs) fabricated at 200 degrees C. The CNT-networks at the conducting substrate increased the charge collection efficiency of the porous TiO2 film, while the short circuit current increased up to ca. 43% under optimized condition. However, the significant decrease in the open-circuit voltage (Voc) up to ca. 132 mV resulted in the failure of the overall cell efficiency improvement. Findings reveal that the transfer process for the back electron is mainly responsible for the significant Voc drop when the MWCNTs were deposited at the electron-collecting substrate of the photoelectrode. The study demonstrates that electrophoretic deposition of MWCNTs on charge collecting substrate would be applicable to introduce an effective charge-collecting channel for the fabrication of flexible DSSCs under low temperature sintering condition.