Ru-based donor-acceptor photosensitizer that retards charge recombination in a p-type dye-sensitized solar cell

• We report on the synthesis and characterization of a donor-acceptor ruthenium polypyridyl complex as a photosensitizer for p-type dye-sensitized solar cells (DSSCs). The electrochemical, photophysical, and photovoltaic performance of two ruthenium-based photosensitizers were tested in NiO-based DSSCs; bis-(2,2′-bipyridine-4,4′-dicarboxylic acid) 2N-(1,10-phenanthroline)-4-nitronaphthalene-1,8-dicarboximide ruthenium(ii), ([Ru(dcb) 2(NMI-phen)](PF 6) 2) and tris-(2,2′-bipyridine-4,4′-dicarboxylic acid) 3 ruthenium(ii), [(Ru(dcb) 3)Cl 2]. The presence of an electron-accepting group, 4-nitronaphthalene-1,8-dicarboximide (NMI), attached to the phenanthroline of [Ru(dcb) 2(NMI-phen)] 2+ resulted in long-lived charge separation between reduced [Ru(dcb) 2(NMI-phen)] 2+ and NiO valence band holes; 10-50 μs. In the reduced state for [Ru(dcb) 2(NMI-phen)] 2+, the electron localized on the distal NMI group. In tests with I 3 -/I - and Co(4,4′-di-tert-butyl-bipyridine) 3 2+/3+ electrolytes, [Ru(dcb) 2(NMI-phen)] 2+ outperformed [Ru(dcb) 3] 2+ in solar cell efficiency in devices. A record APCE (25%) was achieved for a ruthenium photosensitizer in a p-type DSSC. Insights on photosensitizer regeneration kinetics are included.

Subject headings

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

Keyword

1

10-phenanthroline

Charge recombinations

Charge separations

Dicarboxylic acid

Donor-acceptors

Dye-Sensitized solar cell

Dye-sensitized solar cells

Electron-accepting

P-type

Phenanthrolines

Photophysical

Photovoltaic performance

Reduced-state

Ruthenium polypyridyl complexes

Solar cell efficiencies

Valence-band holes

Photoelectrochemical cells

Ruthenium

Ruthenium compounds

Solar cells

Photosensitizers

SRA - Energy

Publication and Content Type

ref (subject category)

art (subject category)