Demagnetization field driven charge transport in a TiO2 based dye sensitized solar cell

• Published in: Solar energy 2019-07, Vol.187, p.281-289
• Main Authors: Kannan, U.M., Giribabu, L., Jammalamadaka, S. Narayana
• Format: Article
• Language: English
• Subjects: Charge transport; Circuits; Computer simulation; Current carriers; Demagnetization; Demagnetizing field; Dye sensitized solar cells; Dyes; Electrochemical impedance spectroscopy; Electrochemistry; Energy; Energy conversion efficiency; Flux density; Impedance spectroscopy; Incident light; Iron oxides; Magnetic fields; Magnetic nanoparticles; Magnetite; Nanoparticles; Phosphorescence; Photovoltaic cells; Recombination; Short circuit currents; Solar cells; Solar energy; Spectroscopy; Titanium dioxide; Transfer matrices
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2019.05.029

•Enhanced efficiency of TiO2 DSSC by demagnetization fields.•Enhanced recombination time due to stray fields.•Evidence for stray fields using magnetic force microscopy and micromagnetic simulations.•Realization of more absorption of the light through transfer matrix modelling. We report on the effect of demagnetizing fields due to magnetite (Fe3O4) nanoparticles (NPs) on the efficiency of TiO2 based dye sensitized solar cells (DSSC). The addition of Fe3O4 NPs into the photoanode enhanced the power conversion efficiency of DSSC. This may be attributed to the magnetic field effect induced by the demagnetizing field produced by the magnetite NPs, which is evident from our micromagnetic simulation. Essentially, such a stray field would induce additional force on the electron motion and thereby enhancing the recombination time of these charge carriers. Enhancement in recombination time is directly evidenced by the increase in short circuit current density. In addition, we have carried out an electrochemical impedance spectroscopy (EIS) study to probe the mechanism of charge transport within the DSSC device. Quenching of intensity in phosphorescence data indeed infer a decrease in recombination rate. We calculated the value of demagnetization energy from NPs with micromagnetic simulations. Absorbed energy density of ‘s’ and ‘p’ polarized incident light estimated using transfer matrix model.