Improve The Maximum Limiting Performance Of Counter Electrode For Dye-Sensitized Solar Cells

Dye sensitized solar cells (DSSCs) have attracted extensive attention since Graztel published his work on this topic in1991. DSSCs have been considered to have great potential as a low-cost photovoltaic energy conversion device due to their simple fabrication process and low-cost.As a photo-electrochemical solar cell, a DSSC typically contains a dye-sensitized photoanode, a counter electrode (CE) and an electrolyte containing iodide/triiodide redox couples. CE is an indispensable park of the DSSC for the electrons are collected in the CE from the external circuit and transferred to the redox couples. The charge transfer rate between the CE and the electrolyte is one of the key factors for the photo-current of the solar cell. To improve the cell’s performance, platinum (Pt) is most commonly used as the catalyst in CEs. However, as a noble metal which has low crustal content, Pt signicantly leads to the high cost of DSSCs. Therefore, much work to search for alternatives to Pt have been done in recent years.In this work, the electrochemical kinetics in counter electrode was analysed and the maximum limiting performance for counter electrode was proposed and analysed. It was found that the maximum limiting performance of Pt counter electrode was as high as20.12%which was more higher than the conversion efficiency of present DSSC. Therefore, we conclude that Pt CE has little negative effect on the performance of DSSC.Moreover, a novel porous fluorine doped tin oxide (PFTO) conductive framework was introduced to CEs for DSSCs. Being modified by carbon or platinum, the framework has higher maximum limiting power conversion efficiency compared with a planar Pt.