Electrophoretic Deposition and Characterization of TiO2/Nb2O5 Composite Thin Films for Dye Sensitized Solar Cells

Abstract

In this study, Electrophoretic Deposition (EPD) technique was used to fabricate TiO2/Nb2O5 composite thin films on FTO coated glass for application as photoelectrodes in Dye Sensitized Solar Cells (DSSC). A TiO2/Nb2O5 ratio of 1:1 was used in a 2-propanol suspension solution with a solid loading of 0.25g/L. Optical investigations showed that the film with thickness of 5.5 m deposited at 35.0 V for 90.0 s had the highest transmittance of 55.0 % at a wavelength () of 1,300 nm. The optical band gap energy (Eg) was 3.884 eV and was found to be dependent on the annealing time. The solar cell fabricated from this film had an open circuit voltage (VOC) of 0.66 V, fill factor (FF) of 57.0%, short current density (JSC) of 5.25 mA/cm2 and photo conversion efficiency (PCE) of 2.0%. Electrochemical Impedance Spectroscopy (EIS) analysis indicate that the DSSC device with thinner photoelectrodes have more efficient electron transport in the photoanode compared to thicker photoelectrodes to achieve higher conversion efficiencies.