Improved dye-sensitized solar cells by composite ionic liquid electrolyte incorporating layered titanium phosphate

We reported a composite electrolyte prepared by incorporating layered alpha-titanium phosphate (alpha-TiP) into a binary ionic liquid of 1-propyl-3-methylimidazolium iodide (PMII) and 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF(4)) (volume ratio, 13:7) electrolyte. The addition of alpha-TiP markedly improved the photovoltaic properties of dye-sensitized solar cells (DSSCs) compared to that without alpha-TiP. The enhancement was explained by improved diffusion of tri-iodide (I-3(-)) ions, suppressed electron recombination with I-3(-) in the electrolyte and increased lifetime of electrons in mesoscopic TiO2 film. (C) 2010 Elsevier Ltd. All rights reserved.