Carbon Nanotube/Manganese Oxide Thin Film Composites-Based Counter Electrode for Dye-Sensitized Solar Cell

Abstract:

Manganese oxide thin film sandwiched between carbon nanotubes thin films-coated on fluorine-doped tin oxide (FTO/CNT/MnO_x/CNT) was used as a counter electrode of dye-sensitized solar cell (DSSC) for performance improvement. The multi-layer electrodes were fabricated by sequential process comprising doctor-blade coating of CNT layer and the following electroplating coating of MnO_x layer and subsequent doctor-blade coating of CNT layer once again. The multi-layered counter electrode of CNT/MnO_x/CNT exhibited the improved conversion efficiency and a fill factor of 2.01±0.01% and a fill factor of 0.55±0.01, respectively, due to an increase in capacitance of the electrode. Electrochemical impedance spectra (EIS) show that the capacitance of multi-layered CNT/MnO_x/CNT electrode increased from 22±3 mF to 41±2 mF comparing to that of a monolayer of CNT. Furthermore, EIS of FTO/CNT/MnO_x/CNT-based DSSC shows the smallest radius of the semicircle with a charge transfer resistance of 42 Ω, implying a quick redox reaction between counter electrode and electrolyte. The improved fill factor is likely due to the role of MnO_x that increases the capacitance of electrode and reduces electron transfer rate from counter electron to electrolyte.

• Periodical: Key Engineering Materials (Volumes 675-676)
• Pages: 269-272
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.675-676.269
• Online since: January 2016
• Authors: Nathakreat Ketama, Wirat Jarernboon, Winadda Wongwiriyapan*
• Keywords: Carbon Nanotube, Counter Electrode, Dye-Sensitized Solar Cell, Manganese Oxide

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