Enhanced photovoltaic conversion efficiency in dye-sensitized solar cells based on photoanode consisting of TiO2/GO/Ag nanofibers

In this study, we used successfully sol-gel method with electrospinning technique to prepare the titanium dioxide (TiO2) nanofibers (NEs) containing graphene oxide (GO) and silver (Ag) nanoparticles (NPs). We modified the photoanode of dye-sensitized solar cell (DSSC) based on various composited TiO2 NFs. TiO2 colloid was first deposited on the fluorine-doped tin oxide (FTO) substrate by a blade coating method. Then, TiO2/GO or TiO2/GO/Ag NF was seeded beside the TiO2 colloid layer as an additional layer on photoanode of the DSSC. With solar simulator under AM 1.5, we discussed the effect of GO and Ag composited TiO2 NFs on photovoltaic conversion efficiency (eta). We discovered that TiO2/GO NF or TiO2/GO/Ag NF seeded on photoanode of DSSC as an additional layer could improve q, increased 16% or 40% respectively, compared with a standard DSSC. Efficiency of TiO2/GO/Ag NF seeded as the additional layer on photoanode of DSSC exhibited significant increase. According to our study, in the interface resistance between internal components analyzed by electrochemical impedance spectroscopy, we found that the additional composited TiO2 NFs layer could prohibit recombination of electrons between the interface of TiO2 and electrolyte, which resulted in the increase of carrier transport impedance. In addition, Ag NPs could be considered as an effective approach to enhance electron harvesting.