Abstract
One way of improving the efficiency of dye-sensitized solar cell (DSSC) is to add small amounts of metallic nanoparticles or nanowires in the electrode to improve the electron transport efficiency. We used the Polyol process to grow silver nanowires and also to synthesize gold nanotubes using the silver nanowires as the templates. TiO2 nanoparticles were coated on the surface of nanowires by sol-gel method. XRD, as well as SEM and TEM were used to characterize the synthesized composite nanostructures. Instead of forming a thin titanium dioxide film, it was found that titanium dioxide nanoparticles were formed on the surface of the silver nanowires. This is advantageous since the total surface area would become much larger as compared with the coating of a smooth thin titanium dioxide film on the silver nanowires. DSSC were fabricated with the addition of silver nanowires, silver nanowires coated with TiO2 nanoparticles, gold nanoparticles, and gold nanowires mixed with the commercial P25 TiO2 nanoparticles, respectively. The open circuit current was improved for all the cases of adding the metallic nanomaterials. The largest improvement was achieved by adding 1 wt% (relative to P25 TiO2 nanoparticles, the highest weight percent case) gold nanotubes. The open circuit current was increased from 9.49 mA/cm2 to 1.77 mA/cm2 and efficiency was increased from 3.68% to 4.27%. Keywords: nanoparticles, nanowires, dye-sensitized solar cell