Experimental and Simulation Studies of Platinum-Free Counter Electrode Material for Titania Aerogel-Based Quasi-Solid Dye-Sensitized Solar Cell

Abstract

Counter electrode is one of the key components in the fabrication of dye-sensitized solar cell (DSSC). It is mainly used to complete the electrical circuit of a solar cell as well as to reduce tri-iodide to iodide at the interface of fluorine-doped tin oxide/electrolyte. Platinum (Pt) is the conventional counter electrode for DSSC assembly. In recent times, lots of research work has been carried out to replace (Pt) with low cost carbon electrodes. In this article, as an alternative to platinum, graphite which is a cost-effective carbon material is used as counter electrode material for DSSC. A DSSC was fabricated using titania aerogel photoanode, graphite counter electrode, gel polymer electrolyte, porphyrin, and N719 dye sensitizers. The photocurrent density-voltage ( J – V ) plots of the fabricated DSSC were measured at one sun illumination. The photocurrent conversion efficiency of graphite-based DSSC was comparable with that of platinum-based DSSC for the N719 dye. The electron transfer process in graphite-based DSSC was explained based on the photo-physical parameters such as relaxation time (τ n ) and diffusion time (τ d ) measurements. The J – V curves were simulated using a MATLAB program to compare with the experimental measurements. There is a good agreement between the simulated and experimental results.