Investigating Tungsten Sulfide as a Counter Electrode Material in Dye-Sensitized Solar Cells.

With the recent interest in renewable energy sources, dye-sensitized solar cells (DSSCs) have received a great deal of attention as a cheaper and more sustainable alternative to silicon-based solar cells. In a DSSC, the counter electrode performs the catalytic reduction of the electrolyte and electron collection. To perform this function adequately, platinum is the preferred material currently. To reduce the dependence of the DSSC on such an expensive material, alternatives such as activated carbon (AC) and two-dimensional transition metal dichalcogenides, and more specifically, tungsten sulfide (WS), were considered. AC has shown great potential as a material for counter electrodes, whereas WS has unique physiochemical properties which warrant its exploration as an energy material. In this article, we synthesized and evaluated the performance of DSSCs with AC, WS, and AC/WS composite counter electrodes. It was demonstrated that the performance of the WS/AC composite counter electrode with a 1:2 ratio of WS to AC shows the highest performance with an efficiency of 6.25%.