Efficient Counter Electrode Manufactured from Ag₂S 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, Ag₂S 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 Ag₂S nanocrystals ink exhibited efficient electrocatalytic activity in the reduction of I₃^- to I^- in DSSCs. The DSSC consisting of Ag₂S 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 Ag₂S CE as a promising alternative to Pt CE in DSSCs. Energy conversion: A counter electrode manufactured from Ag₂S nanocrystal ink exhibited efficient electrocatalytic activity in the reduction of I₃^- to I^- in dye-sensitized solar cells (see figure; DSSCs, η=8.40 %). The simple composition, easy preparation, stable chemical properties and good catalytic performance make the newly developed Ag₂S a promising alternative to Pt in DSSCs.