Synthesis and Characterization of Electrode Nanomaterials for Dye - Sensitized Solar Cell Fabrication

L.V. Nghiem, N.T. Hoang, P.T. Hien, L.M.L. Phung, V.T. Long, N.T.P. Thoa
Vietnam National University - Ho Chi Minh City, VN

Keywords: dye-sensitized solar cell, titanium dioxide, platinum, carbon nanotube

Summary:

In this work nanomaterials for photoanode and cathode of the dye-sensitized solar cells (DSCs) have been synthesized and used for fabrication of DSCs. The morphology, crystal structure and electrochemical behavior of the synthesized materials and films were characterized by SEM, TEM, XRD, EDX, nitrogen adsorption, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Photovoltaic performance of fabricated DSCs was evaluated by I-V curves, open-circuit voltage decay and EIS measurements. A mixture of anatase titanium dioxide (a-TiO2) and TiO2 fusiform nanorods (TiO2-f) was used to prepare DSC photoanode. a-TiO2 nano particles were synthesized by a hydrothermal sol-gel method, while TiO2-f obtained by modification of commercial Degussa P25 (TiO2-P25). The effect of TiO2-f content in photoanode on DSC performance was investigated and it was found that 5 wt% TiO2-f improved Isc and cell efficiency. Nanostructured Pt films for DSC cathode were prepared by polyol reduction (PR-Pt), electrodeposition (ED-Pt) and thermal decomposition (TD-Pt). TD-Pt counter electrode show the best performance with stable photovoltaic characteristics. The DSC efficiency decreased in the order TD-Pt>ED-Pt>PR-Pt. The highest catalytic activity for triiodide/iodide redox reaction was observed for ED-Pt. Meanwhile the reduction of I3 ions on TD-Pt has the lowest overpotential, compared with ED-Pt and PR-Pt.