Sol-gel derived cobalt sulphide as an economical counter electrode material for dye sensitized solar cells

In this study, a solution-derived cobalt sulfide (CoS) was utilized as counter electrode (CE) in dye sensitized solar cell (DSSC). It is show that high-quality CoS nanocrystals (10 ∼ 500 nm) can be formed by post annealing process at temperatures above 500 °C. The deposited CoS nanocrystals effectively replace the commonly used platinum. Photovoltaic measurements revealed that the DSSCs assembled with the CoS CE showed excellent performance with open voltage of around 0.64 V, short circuit current of 7.1 mA/cm2 and power conversion efficiency of around 5%.