Enhanced charge collection in dye-sensitized solar cells utilizing collector–shell electrodes

•ITO–TiO2 collector–shell electrodes prepared by screen-printing and TiCl4 treatment.•DSCs using these electrodes exhibit a best power conversion efficiency of 3.3%.•Charge transport is fast in DSCs utilizing the collector–shell electrodes.

Nanostructured porous tin-doped indium oxide (ITO) films were prepared by screen printing of an ITO nanoparticle paste onto conducting fluorine-doped tin oxide (FTO) substrates. The ITO films were subsequently coated with thin layers of TiO2 by the hydrolysis of TiCl4 to form the collector–shell photoelectrodes. The morphology of films was analysed by scanning electron microscope (SEM). It was found that a uniform coating of TiO2 was achieved when three or more deposition cycles were applied. Dye-sensitized solar cells were constructed with the collector–shell photoelectrodes using an electrolyte containing the [Co(bpy)3]2+/3+ (bpy = 2,2′-bipyridine) redox couple and MK-2, an organic sensitizer and efficiencies of 3.3% achieved. Charge transport in cells utilizing the collector–shell electrodes was found to be 2–6 times faster than those utilizing P25-based TiO2 electrodes.

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