Preparation of platinum-free tubular dye-sensitized solar cells by electrophoretic deposition

Abstract

Tubular dye-sensitized solar cells (DSSCs) were developed by replacing expensive materials with lower cost materials as follows: (1) replacing conductive glass electrodes with titanium (Ti) wires and (2) replacing platinum (Pt) catalyst with the mixture of multi-walled carbon nanotubes, MWCNTs and Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), PEDOT-PSS. Platinized counter electrodes were used as the standard counter electrodes for comparison. The effects of the chemical treatment of titanium wire substrate and electrophoretic deposition condition on the efficiency of DSSCs were also investigated. The chemical treatment of titanium wires was carried out by soaking the wires in HF-HNO3 solutions at three different concentrations of 0.8, 1.6 and 2.4 M and three different soaking durations of 5, 10 and 15 min. The optimum condition was found at HF-HNO3 concentration of 0.8 M and soaking duration of 10 min. Film coating on working electrodes was performed using electrophoretic technique at three different voltages of 5, 8 and 10 V and four different coating durations of 1, 3, 5 and 7 min. Then, the optimum condition at deposition voltage of 5 V and deposition duration of 5 min was applied for film deposition on counter electrodes. The efficiency of DSSC with CNTs/TiO2 counter electrode was 0.03%. The addition of PEDOT-PSS improved the efficiency of DSSC to 0.08%.

Keywords

• Tubular dye-sensitized solar cell
• Platinum –free solar cell
• Electrophoretic deposition
• Carbon nanotubes
• PEDOT-PSS