Control of dark current in photoelectrochemical (TiO2/I––I3–) and dye-sensitized solar cells

Abstract

The ruthenium complex bis-tetrabutylammonium cis-dithiocyanato-N,N'-bis-2,2'-bipyridine-4-carboxylic acid, 4'-carboxylate ruthenium(II), N-719, was found to block the dark current of dye sensitized solar cells (DSC), based on mesoporous TiO2 films deposited on a F-doped tin oxide electrode and the effect was compared to surface treatment by TiCl4 and the introduction of a compact TiO2 blocking layer.

ZnO−Al2O3 and ZnO−TiO2 Core−Shell Nanowire Dye-Sensitized Solar Cells

“…The investigation of compact TiO 2 layers in electrolyte cells began only recently and involves an ongoing debate. [59][60][61][62] Here we compare ALD-made TiO 2 blocking layers in nanowire and nanoparticle cells to highlight the differences between the two DSC architectures and to add to this debate.…”

Optimization of nanostructured titania photoanodes for dye-sensitized solar cells: Study and experimentation of TiCl4 treatment

“…The pre-treatment influences positively the bonding strength between the FTO substrate and the porous TiO 2 layer and blocks the charge recombination between electrons emanating from the FTO and the I 3 − ions present in the I − /I 3 − red-ox couple [12]. To reduce the charge recombination at the FTO/electrolyte interface, Ito and his coworkers have demonstrated that a high open circuit photo-voltage is required to prevent the recapture of photo-injected electrons by I 3 − [13].…”

Biomimetic Dye Aggregate Solar Cells

“…The treatment in TiCl 4 is assumed to increase the dye uptake and to increase the electron injection rate [125]. However, the kink, which is the most important factor decreasing the fill-factor and efficiency, remained almost unaffected.…”

“…This is due to the formation of an ohmic contact between spiro-MeOTAD and the FTO. Nowadays such blocking layers are used for DSSCs with liquid electrolytes, too, in order to further improve the efficiency [125], especially at low light intensities [126] and for organic dyes, which benefit, in contrast to ruthenium polypyridine dyes, significantly by the blocking layer. The efficiency of DSSCs with organic dyes and a hole blocking layer increased by a factor of 1.6 at full light intensity and up to a factor of 2 at low light intensities [127] compared to cells without the hole blocking layer.…”