Co-dominant effect of selected natural dye sensitizers in DSSC performance

Abstract

Natural dyes from Ixora coccinea (RX) and Bougainvillea sp. (BG) were extracted and these individual dyes as well as the cocktail dye of RX and BG (1:1v/v ratio) were investigated as dye sensitizers in dye sensitized solar cells (DSSCs). To analyze the capability of the dyes, various characterization methods were deployed such as incident photon-to-current efficiency (IPCE), current-to-voltage (I-V) characteristics, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that DSSC sensitized with RX performed the best with η=0.76%, followed by the cocktail dye (η=0.40%) and BG (η=0.21%). This best overall performance of RX was attributed to the charge transport resistance (Rtr=3.89Ω), with the highest electron density (ɳs=9.45×1028) and effective diffusion coefficient (Deff=2.43×10−8m2/s), which accounted for high Jsc. Co-dominance performance of DSSC sensitized with cocktail dye was observed where the cocktail dye has demonstrated an improved Voc as compared to RX and improved Jsc against BG, suggesting individual influence from both dyes.