Nanoporous Reduced Graphene Oxide and Polymer Composites as Efficient Counter Electrodes in Dye-Sensitized Solar Cells
Vediappan Sudhakar, Anup Kumar Singh, Mrinmoy Kumar Chini
Abstract
The introduction of an efficient and precious platinum (Pt) free counter electrode (CE) for dye-sensitized solar cells (DSSCs) is an important aspect to address. In this report, we have employed nanoporous reduced graphene oxide (PG) containing PEDOT:PSS–PG composite on FTO substrate as CEs, which have shown excellent diffusion of I3–, remarkable photocatalytic activity, and better device performance along with desired stability. The investigated cathode material has been prepared by mixing PGs and highly conducting PEDOT:PSS. Experimental measurements and analyses such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and so on indicate that PEDOT:PSS–PG is a promising cathode material for a Pt-free CE in DSSCs. EIS indicates that the PEDOT:PSS–PGs have lower interfacial charge-transfer resistance because of their high electrical conductivity and superior electrocatalytic activity. The achieved photoconversion efficiency (η) of a DSSC employing the Pt-free PEDOT:PSS–PG/FTO CE is 9.57%, which is found to be comparable to that of Pt/FTO CE based DSSC (9.64%) under a simulated solar light illumination of 100 mW/cm2.