Facile synthesis of GO@SnO2/TiO2 nanofibers and their behavior in photovoltaics

Chemical doping is a widely-used strategy to improve the performance of TiO₂ for the dye-sensitized solar cells (DSCs). However, the effect of two efficient dopants has been rarely investigated. We present the synthesis of GO@SnO₂/TiO₂nanofibers (NFs) by a facile method using electrospinning and hydrothermal processes. The synthesized NFs are described in terms of morphology, crystallinity and chemistry through FESEM, TEM, HR-TEM, XRD, EDX, XPS, FT-IR and Raman spectra. As the results, the axial ratio and the average diameter of NFs decreased after the hydrothermal treatment and calcinationprocess, respectively. The prepared Titania-based nanofibers have 81.82% anatase and 18.18% rutile-structure. The developed materials are applied as working electrodes of DSCs. The photovoltaic performances showed that the efficiency of the device employed GO@SnO₂/TiO₂ photoanode gave 5.41%, which was higher than those of cells fabricated with SnO₂/TiO₂ NFs (3.41%) and GO@TiO₂ NFs (4.52%) photoanodes. The photovoltaicparameters such as J_sc, V_oc, FF and R_ct are calculated and found to be 11.19 mA cm⁻², 0.72 V, 0.67 and 9.26 Ω, respectively. The high photovoltaic response of DSC based of GO@SnO₂/TiO₂ NFs may be attributed to the large surface area of the NFs, and the low electron recombination. Furthermore, the start-stop switches of the cell devices with the developed photoanode affirmed the stability and photovoltaic performance of the cell.