Influence of SrTi1-x CoxO3 NPs on electrocatalytic activity of SrTi1-xCoxO3 NPs/PEDOT-PSS counter electrodes for high efficiency dye sensitized solar cells

Dye sensitized solar cell (DSSC) based on the improvement of cell performance by modification of cell components is still an interesting issue to be explored. Consequently, various natural dyes and materials/ compounds have been investigated to replace the expensive synthetic dye and Pt counter electrode (CE), respectively. According to our previous work on the study of transition metal doped SrTiO3 nanoparticles (NPs), it was obvious that various properties of these materials could be altered with potential to apply for different devices. In this work, it is our purpose to search for a novel composite material based on Codoped SrTiO3 NPs to replace Pt CE. Therefore, composite SrTi1-x CoxO3 NPs/PEDOT-PSS pastes (x = 0, 0.025, 0.05, 0.075 and 0.1) were prepared and tested for CE of DSSC. Interestingly, the cyclic voltammetry (CV) measurements indicated that SrTi1-xCoxO3 NPs could function as an excellent catalyst in iodide/ triiodide redox reaction. Moreover, electrochemical impedance spectroscopy (EIS) results showed the consistent reduction of charge transfer resistance of SrTi1-xCoxO3 NPs/PEDOT-PSS CE. Surprisingly, the highest solar energy conversion efficiency of 8.39%, compared with 8.27% of Pt CE, was achieved in a cell with SrTi0.925Co0.075O3 NPs/PEDOT-PSS CE. (C) 2018 Elsevier Ltd. All rights reserved.