Bifurcation of Regeneration and Recombination in Dye-Sensitized Solar Cells via Electronic Manipulation of Tandem Cobalt Redox Shuttles.
A cobalt(IV/III) redox shuttle, cobalt tris(2-(p-tolyl)pyridine), [Co(ptpy)3]+/0, was synthesized and investigated for use in dye-sensitized solar cells, DSSCs. An incredibly fast self-exchange rate constant of (9.2 ± 3.9) × 108M-1s-1was determined for [Co(ptpy)3]+/0, making it an ideal candidate for dye regeneration. To avoid fast recombination and solubility limitations, we utilized a tandem electrolyte containing [Co(ptpy)3]+/0and cobalt tris(2,2'-bipyridine), [Co(bpy)3]3+/2+. An improved short circuit current density is achieved for DSSCs employing the tandem electrolyte, compared to electrolytes containing only [Co(bpy)3]3+/2+, consistent with superior dye regeneration expected based on predictions using Marcus theory, which is also discussed.
Department of Chemistry, Michigan State University , 578 S Shaw Lane, East Lansing, Michigan 48824-1322, United States.
Josh
J
Baillargeon
Department of Chemistry, Michigan State University , 578 S Shaw Lane, East Lansing, Michigan 48824-1322, United States.
Yuling
Y
Xie
Department of Chemistry, Michigan State University , 578 S Shaw Lane, East Lansing, Michigan 48824-1322, United States.
Thomas W
http://orcid.org/0000-0001-6917-7494
TW
Hamann
Marcus theory; cobalt redox shuttles; dye-sensitized solar cells; electron transfer; regeneration; self-exchange