Insight into electrochemical properties of Co3O4–modified magnetic polymer electrolyte

Agarose–based electrolyte containing magnetic Co 3 O 4 nanoparticles is studied for quasi–solid–state dye–sensitized solar cells (DSSCs) under external magnetic field treatment. SEM studies reveal the existence of oriented microstructure in Co 3 O 4 –modified agarose electrolyte film under proper magnetic field intensity. The formation mechanism of this ordered structure induced by magnetic field is analyzed. The impedance analysis shows that the ionic conductivity of Co 3 O 4 –modified agarose electrolyte is obviously increased by applying magnetic field intensity of 25   mT. Improved electron recombination process and photoelectric performance are observed in DSSCs under certain magnetic field treatment by electrochemical impedance spectra (EIS) and photovoltaic studies. The DSSC treated with magnetic field can maintain the efficiency unchanged for 434   hours without sealing. This is attributed to the high ionic conductivity and improved electron transfer process in DSSC resulting from the magnetic field treatment. Comparison of photovoltaic performances for Co 3 O 4 and NiO modified DSSCs under 25   mT magnetic field treatment shows that Co 3 O 4 -modified DSSC exhibits higher energy conversion efficiency than that of NiO-modified one at the same condition.