Efficient Counter Electrode Manufactured from Ag2 S Nanocrystal Ink for Dye-Sensitized Solar Cells

It is generally believed that silver or silver-based compounds are not suitable counter electrode (CE) materials for dye-sensitized solar cells (DSSCs) due to the corrosion of the I(-) /I3 (-) redox couple in electrolytes. However, Ag2 S has potential applications in DSSCs for catalyzing I3 (-) reduction reactions because of its high carrier concentration and tiny solubility product constant. In the present work, CE manufactured from Ag2 S nanocrystals ink exhibited efficient electrocatalytic activity in the reduction of I3 (-) to I(-) in DSSCs. The DSSC consisting of Ag2 S CE displayed a higher power conversion efficiency of 8.40 % than that of Pt CE (8.11 %). Moreover, the devices also showed the characteristics of fast activity onset, high multiple start/stop capability and good irradiated stability. The simple composition, easy preparation, stable chemical property, and good catalytic performance make the developed Ag2 S CE as a promising alternative to Pt CE in DSSCs.