Polyaniline (PANI)/reduced graphene oxide (rGO) composite as a counter electrode for dye solar cells.

Abstract

Polyaniline (PANI)-reduced graphene oxide (rGO) based transparent counter electrodes have been fabricated for dye sensitized solar cells as an alternative to the expensive platinum (Pt) counter electrodes. Here, the graphene oxide (GO) added during the polymerization of PANI will subsequently reduce to rGO. The concentration of graphene oxide (GO) was varied in PANI matrix to optimize the performance of dye solar cell (DSC). With 1% GO addition in PANI, 9.68% current density was increased, consequently, 13.9% photocurrent density was found to be increased as compared to pure PANI. Electrochemical impedance spectroscopy (EIS) disclosed that the incorporation of 1% GO in PANI caused the double-layer capacitance to increase by 10 times compared to pure PANI. This implies that graphene is capable of enhancing the specific surface area and catalytic capacity of PANI. Optical transparency of PANI-1% GO counter electrode was found to be ∼67% between the wavelengths of 500 to 600 nm. Such transparency enables the construction of bifacial DSCs. Although the photo conversion efficiency (PCE) of DSC with PANI-1% GO counter electrode is still not comparable to the one with Pt counter electrode but it is sufficient to be considered as the replacement as it exhibits good photovoltaic performance and optical characteristics together with an exceptionally low cost material.