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 ?uorine-doped tin oxide (FTO), were employed as charge-collecting channels in the TiO ₂ photoelectrode of dyesensitized solar cells (DSSCs) fabricated at 200 °C. The CNT-networks at the conducting substrate increased the charge collection ef?ciency of the porous TiO ₂ ?lm, while the short circuit current increased up to ca. 43% under optimized condition. However, the signi?cant decrease in the opencircuit voltage (V _oc) upto ca. 132 mV resulted in the failure of the overall cell ef?ciency improvement. Findings reveal that the transfer process for the back electron is mainly responsible for the signi?cant V _oc 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 ?exible DSSCs under low temperature sintering condition.