Iron Redox Shuttles with Wide Optical Gap Dyes for High‐Voltage Dye‐Sensitized Solar Cells

Abstract

A series of iron polypyridyl redox shuttles were synthesized in the 2+ and 3+ oxidation states and paired with a series of wide optical gap organic dyes with weak aryl ether electron‐donating groups. High voltage dye‐sensitized solar cell (HV‐DSC) devices were obtained through controlling the redox shuttle energetics and dye donor structure. The use of aryl ether donor groups, in place of commonly used aryl amines, allowed for the lowering of the dye ground‐state oxidation potential which enabled challenging to oxidize redox shuttles based on Fe2+ polypyridyl structures to be used in functional devices. By carefully designing a dye series that varies the number of alkyl chains for TiO2 surface protection, the recombination of electrons in TiO2 to the oxidized redox shuttle could be controlled, leading to HV‐DSC devices of up to 1.4 V.

Bio and non‐bio materials‐based quasi‐solid state electrolytes in DSSC : A review

“…Besides, these are other types of electrolyte such as transition metal‐based complexes ([Co(bpy‐pz) 2 ] 2+/3+ , CuI/II(tmby) 2 , [Ni(carbollide) 2 ] −/0 , Fe(bpy) 3 3+/2+ , ferrocenylthiophene) 43‐46 and also carbon‐based redox‐active molecules (hydroquinone, guanidine, quinoxaline) 47‐49 . The benefit of using these non‐iodide‐based electrolytes allows the DSSC to operate at a higher potential window up to 1.4 V 45,50 …”

“…42 The illustration of operation principles in terms of electron flow in the DSSC is shown in Figure , ferrocenylthiophene) [43][44][45][46] and also carbon-based redox-active molecules (hydroquinone, guanidine, quinoxaline). [47][48][49] The benefit of using these non-iodide-based electrolytes allows the DSSC to operate at a higher potential window up to 1.4 V. 45,50 The Nasar group developed the fifth-generation polyurethane dendrimer end-capped with 2,2,6,6-tetrame thylpiperidin-1-oxyl (TEMPO), which can partially reduce the amount of liquid I À /I 3 À solution. 51 They can achieve a good performance (short circuit current density, J sc = 16.48 mA/cm 2 , open-circuit voltage, V oc = 0.76 V, fill factor, FF = 0.76, and PCE = 9.54%) when reducing the liquid I À /I 3 À solution to 50%.…”

A versatile iron [1-(naphthalen-2-ylmethyl)-2-(pyridin-2-yl)-1H-benzo[d]imidazole]3 metal complex redox active material for energy conversion and storage systems

“…These results motivate the use of highly active Fe-based electrolytes for the development of next-generation DSCs with higher PCEs. 14,15…”

Photophysical Properties of Donor–Acceptor−π Bridge–Acceptor Sensitizers with a Naphthobisthiadiazole Auxiliary Acceptor: Toward Longer-Wavelength Access in Dye-Sensitized Solar Cells

“…Importantly, the BTD building block , has been used in nearly all of the highest efficiency and highest photovoltage generating DSSC devices (Figure ). − However, A′-type building blocks that enable longer-wavelength absorption are needed to improve further substantially. The limited conjugation length and withdrawing strength of the BTD building block are design elements that can be significantly improved upon.…”