Graphene-based cathodes for liquid-junction dye sensitized solar cells: Electrocatalytic and mass transport effects

The optimization of mediator/cathode in a dye sensitized solar cell (DSC) requires detailed knowledge about their electrochemical properties. Particularly, the kinetics of mediator's turnover on the cathode and the mass transport of mediator in the electrolyte solution are the crucial parameters which influence the overall efficiency of solar energy conversion in DSC. This review article aims at critical survey of the works carried out in the field. Attention is paid to graphene-based materials for the counter electrode, which may, eventually, meet all the benchmark parameters for a good DSC cathode, i.e. high optical transparency and electrical conductivity associated with high electrocatalytic activity for the redox mediator. So far, platinum and transparent conducting oxide (TCO) electrodes were used ubiquitously in DSC cathodes, but there is a motivation to avoid Pt and TCO to decrease the device cost without compromising of its performance. (C) 2013 Elsevier Ltd. All rights reserved.