31876-74-1Relevant academic research and scientific papers
Photovoltaic properties of TiO2 loaded with glutathione- protected silver clusters
Sakai, Nobuyuki,Nakamura, Satoshi,Tatsuma, Tetsu
, p. 16162 - 16165 (2013/11/19)
Glutathione-protected Ag clusters (Ag15, Ag25 and Ag29) function as photosensitizers when they are adsorbed on TiO 2 electrodes. [Co(bpy)3]2+ is the most appropriate electron donor among the cobalt complexes examined. Ag15 clusters yielded the highest internal quantum efficiency of 28% at 460 nm in the presence of [Co(bpy)3]2+ as a donor.
Design of organic dyes and cobalt polypyridine redox mediators for high-efficiency dye-sensitized solar cells
Feldt, Sandra M.,Gibson, Elizabeth A.,Gabrielsson, Erik,Sun, Licheng,Boschloo, Gerrit,Hagfeldt, Anders
, p. 16714 - 16724 (2011/02/27)
Dye-sensitized solar cells (DSCs) with cobalt-based mediators with efficiencies surpassing the record for DSCs with iodide-free electrolytes were developed by selecting a suitable combination of a cobalt polypyridine complex and an organic sensitizer. The effect of the steric properties of two triphenylamine-based organic sensitizers and a series of cobalt polypyridine redox mediators on the overall device performance in DSCs as well as on transport and recombination processes in these devices was compared. The recombination and mass-transport limitations that, previously, have been found to limit the performance of these mediators were avoided by matching the properties of the dye and the cobalt redox mediator. Organic dyes with higher extinction coefficients than the standard ruthenium sensitizers were employed in DSCs in combination with outer-sphere redox mediators, enabling thinner TiO2 films to be used. Recombination was reduced further by introducing insulating butoxyl chains on the dye rather than on the cobalt redox mediator, enabling redox couples with higher diffusion coefficients and more suitable redox potential to be used, simultaneously improving the photocurrent and photovoltage of the device. Optimization of DSCs sensitized with a triphenylamine-based organic dye in combination with tris(2,2′-bipyridyl) cobalt(II/III) yielded solar cells with overall conversion efficiencies of 6.7% and open-circuit potentials of more than 0.9 V under 1000 W m-2 AM1.5 G illumination. Excellent performance was also found under low light intensity indoor conditions.
Metal-directed assembly of combinatorial libraries - Principles and establishment of equilibrated libraries with oligopyridine ligands
Brisig, Barbara,Constable, Edwin C.,Housecroft, Catherine E.
, p. 1437 - 1447 (2008/02/13)
The cobalt(ii) complexes [Co(bpy)3][PF6]2, [Co(Me2bpy)3][PF6]2 (Me 2bpy = 4,4′-dimethyl-2,2′-bipyridine) and [Co(phen) 3][PF6]2 give paramagnetically shifted 1H NMR spectra which may be fully assigned; the complexes are labile and ligand exchange is complete within mixing time in CD3CN solutions to give libraries of heteroleptic complexes which have been fully characterised by one- and two-dimensional 1H NMR spectroscopy. A library comprising mer and fac isomers of [CoL3]2+ (L = 2,2′-bipyridine-5-carbaldehyde) can be amplified by specific reaction of the fac stereoisomer with a triamine to give a new hexadentate ligand, although other ligand exchange processes compete. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
