Effect of heterocyclic nitrogen ionic liquid additives on the rate of backreaction in DSSCS: An electrochemical characterization

The backreaction in dye-sensitized solar cells (DSSCs) was long ago recognized as one of the main causes of decreasing energy conversion efficiency. Hence, many different approaches have been attempted to reduce the backreaction. In the present work, we use nitrogen additives in the electrolyte to reduce the backreaction with TiO2 and I3−. Intensity-modulated photocurrent/photovoltage (IMPS/IMVS) and charge extraction (CE) techniques are used to obtain information on the dynamics of charge carriers in DSSCs assembled with and without nitrogen additives. The passivation process occurring on the nanoparticles, which is promoted by the additives, prevents recombination but does not change the electron transport time. Therefore, the description of transport and electron recombination kinetics in DSSCs is well established in this work with the emerging IMPS, IMVS, and CE techniques. •Conversion efficiency of DSSC had improved.•The methods IMPS/VS and CE evaluated electrolyte/electrode interface.•Ionic liquids formed a block layer on TiO2 surface.•The backreaction was decreased.•Ionic liquids have no role in TiO2 electron transport smoothing.