Donor‐π‐Acceptors Containing the 10‐(1,3‐Dithiol‐2‐ylidene)anthracene Unit for Dye‐Sensitized Solar Cells

Abstract

Two donor-acceptor molecular tweezers incorporating the 10-(1,3-dithiol-2-ylidene)anthracene unit as donor group and two cyanoacrylic units as accepting/anchoring groups are reported as metal-free sensitizers for dye-sensitized solar cells. By changing the phenyl spacer with 3,4-ethylenedioxythiophene (EDOT) units, the absorption spectrum of the sensitizer is red-shifted with a corresponding increase in the molar absorptivity. Density functional calculations confirmed the intramolecular charge-transfer nature of the lowest-energy absorption bands. The new dyes are highly distorted from planarity and are bound to the TiO(2) surface through the two anchoring groups in a unidentate binding form. A power-conversion efficiency of 3.7% was obtained with a volatile CH(3)CN-based electrolyte, under air mass 1.5 global sunlight. Photovoltage decay transients and ATR-FTIR measurements allowed us to understand the photovoltaic performance, as well as the surface binding, of these new sensitizers.

Dye aggregation identified by vibrational coupling using 2D IR spectroscopy

“…The efficiency of charge transfer depends on many factors, including the photosensitizer electronic orbitals, conjugation of the linker, and the anchoring groups. [5][6][7][8][9][10][11][12][13][14][15] For example, differing levels of conjugation have been shown to inject electrons with different, sometimes multiexponential, kinetics, and different binding groups also show different efficiencies of charge transfer. 11,12 Dye orientation on the surface also has a large effect, as a dye molecule that is lying flat usually has different electron transfer rates than those perpendicular to the surface.…”

Real Sociedad Española de Química Prizes 2013

“…Delgado’s research is focused on the synthesis of carbon‐based energy‐storing materials for the development of efficient photovoltaic devices. He has reported in Chemistry—A European Journal on donor–π‐acceptor molecules for dye‐sensitized solar cells 7…”

2H‐Dinaphthopentacene: A Polycyclic Aromatic Hydrocarbon Core for Metal‐Free Organic Sensitizers in Efficient Dye‐Sensitized Solar Cells

“…Thereby, we have turned our interest to anthracene, which has been previously used as the building block of organic dyes for dye‐sensitized solar cells (DSCs), but all these dyes only displayed a low or moderate PCE 5. In our initial exploration of anthracene related chemistries, we envision a nonacyclic aromatic hydrocarbon, 9,19‐dihydrodinaphtho[3,2,1‐ de :3′,2′,1′‐ op ]pentacene (DNP, Figure 1 ), which can be decorated with four 4‐hexylphenyl groups to allow for a soluble target compound.…”