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

We reported a composite electrolyte prepared by incorporating layered α-titanium phosphate (α-TiP) into a binary ionic liquid of 1-propyl-3-methylimidazolium iodide (PMII) and 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF4) (volume ratio, 13:7) electrolyte. The addition of α-TiP markedly improved the photovoltaic properties of dye-sensitized solar cells (DSSCs) compared to that without α-TiP. The enhancement was explained by improved diffusion of tri-iodide (I3-) ions, suppressed electron recombination with I3- in the electrolyte and increased lifetime of electrons in mesoscopic TiO2 film.