We study the spontaneous recovery phenomenon displayed by solar cells sensitized with a ruthenium complex-based dye N719, whichmanifests with the increase over the time (from several minutes up to some days) of the short circuit current density Jsc and the opencircuit voltage Voc, during cell illumination. Under dark conditions the current decreases over time after the application of forward biasvoltages. We investigate the effects of temperature and electrolyte composition by means of current–voltage measurements and electrochemicalimpedance spectroscopy, both under dark and illumination conditions. The main result is that the recovery of the performancesdepends on the charge transport mechanism at the TiO2/electrolyte interface and is caused by the increasing of the electron lifetime in thetitania. This effect could be explained by intercalation of ions H+ present in the electrolyte that limits the recombination of electrons fromTiO_2 to the triiodide.
|Numero di pagine||11|
|Stato di pubblicazione||Published - 2016|
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