Solid state dye-sensitized solar cells prepared by infiltrating a molten hole conductor into a mesoporous film at a temperature below 150 °C

Infiltration of a molten hole conductor in a mesoporous film at an elevated temperature exhibits good wetting performance and the procedure is therefore suitable as part of the preparation method for solid state dye-sensitized solar cells. Herein, we present a system prepared by infiltrating 4-(diethyl-amino)benzaldehyde-1,1)-diphenyl-hydrazone in its molten form at a temperature below 150 °C. The system displays a maximum photon-to-current conversion efficiency of about 35%, a value corresponding to an increase of about 5 times in comparison with a previously published system prepared by infiltrating a molten hole-conductor at a temperature exceeding 250 °C. By means of comparing charge transport and recombination with the results measured for a liquid analogue, we conclude that whereas the transport rates are similar, recombination is significantly more rapid in the solid-state device.