Abstract
A new tandem electrolyte composed of two redox pairs, the organic radical 2-azaadamantane-
N
-oxyl (AZ) and the well-known redox pair [Co(bpy)
3
]
3+/2+
was investigated in dye sensitized solar cells. Importantly, an increase in
V
OC
was achieved using the new tandem redox system with values up to 1007 mV, compared to only 896 mV for the reference [Co(bpy)
3
]
3+/2+
couple. Consequently, the tandem electrolytes presented higher device performance in conjunction with the organic dye XY1. It was determined that the
V
OC
improvement is mainly attributed to the combined effect of two factors: the more positive redox potential of the small donor AZ (0.81 V
vs.
SHE) and improved recombination resistance in the tandem electrolytes.