Conducting polymer and titanium carbide-based nanocomposites as efficient counter electrodes for dye-sensitized solar cells

Nanocomposite films of titanium carbide (TiC) and poly(3,4-ethylenedioxythiophene) (PEDOT) were developed as an alternative electrocatalyst for dye-sensitized solar cell (DSC) applications. The conducting TiC template was prepared by doctor-blading a TiC nanoparticle dispersion onto transparent conductive oxide (TCO) coated glass, followed by heat treatment at 450-550 °C under inert atmosphere. The counter electrodes were then completed by electrodepositing PEDOT into the TiC hard-template films. Cyclic voltammetry measurements show that the TiC-PEDOT composites exhibited excellent catalytic activity towards the I−/I3− redox reaction. DSCs constructed with the TiC-PEDOT counter electrodes had a significantly improved fill factor and photovoltaic conversion efficiency compared to cells with only TiC particle film counter electrodes. The photovoltaic performance of the DSCs with the TiC-PEDOT electrocatalyst is very similar to those using Pt. With further improvements in conductivity, this combination of conducting inorganic template and conducting polymer electrocatalyst has the potential to be used as a TCO-free electrode to further reduce the materials costs of DSCs.