Carbon nanohorns functionalized PEDOT:PSS nanocomposites for dye sensitized solar cell applications

Single wall carbon nanohorns (SWCNH) functionalized poly 3,4-ethylene dioxythiophene:Polystyrene sulphonate (PEDOT:PSS) composites were developed by reaction of PEDOT:PSS with different weight ratio (0.05, 0.1, 0.2, 0.3, 0.4 wt%) of SWCNH, used as counter electrodes for dye sensitized solar cells (DSSC). Transmission electron microscopy confirms “dahlia” like flowers or buds, having an overall diameter of tens of nm. Cyclic-voltammetric studies of 0.3 wt% composite gives faster I⁻/I₃ ⁻ reaction rate, high surface area. Electrochemical impedance spectroscopy revealed series resistance (R_S) and charge transfer resistance (R_ct) of 0.3 wt% composite DSSC of 20.93, 83.79 Ω respectively, these values were lower compared with the other DSSCs. Photocurrent density–voltage measurements shown the enhanced conversion efficiency (η) of 4.70 % for 0.3 wt% composite, whereas for pure PEDOT:PSS η = 3.66 % and pristine SWCNH of η = 1.94 %. The improved conversion efficiency was due to the combinational superior electrocatalytic activity, reduced R_S, R_ct. This study reveals PEDOT:PSS with SWCNH composite films were possible low cost catalysts for DSSC applications.