Magnetic field-assisted enhancement in efficiency of hybrid TiO2/spinel ferrite nanocomposite-based DSSCs

Abstract

The possibility of tuning and enhancing the performance of dye-sensitized solar cells (DSSCs) containing magnetic nanoparticles (NPs) by external stimulus such as magnetic fields may find applicability in a wide range of applications, including photovoltaic devices. Here, pure TiO2 NPs and TiO2/CoFe2O4 photocatalytic nanocomposites with different CoFe2O4 NP concentrations (1–5 wt.%) are prepared, followed by investigating their morphological, chemical, structural, and magnetic properties by FE-SEM, XRD, and VSM measurements. The power conversion efficiency (η) is examined under internal and external magnetic field effects using solar cell (I-V) characteristics measurements, involving an improvement in the interaction of light with the anchored dye molecules of the nanocomposites with spinel ferrite crystal structure. The performance of short circuit current (JSC) increases by 12.3% for pure TiO2 NPs when applying an external magnetic field of 700 Oe. By systematically investigating the impact of magnetizing and demagnetizing fields caused by CoFe2O4 NPs on the efficiency of DSSCs with TiO2 photoanode, remarkable enhancements in JSC and η (up to about 60% and 28%) are observed under the application of the external magnetic field, which can be related to the shortening of the time required for the charge carriers to recombine due to an increase in the force exerted on the velocity of the electrons. However, η of the fabricated DSSCs is reduced by increasing the CoFe2O4 NP concentration. The reliability of the hybrid nanocomposites is confirmed by repeating the experiments for at least 3 times, indicating no obvious changes in the degradation efficiency.