Efficiency improvement in dye sensitized solar cells by the plasmonic effect of green synthesized silver nanoparticles

In the present investigation, the power conversion efficiency of dye-sensitized solar cells has been remarkably increased by incorporation of green synthesized silver nanoparticles into TiO2 photoanodes. Uniform silver nanoparticles were developed by treating silver ions with Peltophorum pterocarpum flower extract at room temperature. The obtained silver nanoparticles have been characterized by UV-vis. spectroscopy, X-ray Diffraction analysis and Transmission Electron Microscopy (TEM). The X-ray diffraction analysis showed that the obtained silver nanoparticles were polycrystalline in nature with face centered cubic lattice. Silver nanoparticles, with an approximate size in the range of 20-50 nm were examined by the TEM. The plasmonic nanocomposite material was prepared by mixing different green synthesized silver nanoparticles (Ag content of 1, 2 and 3 wt%) with P25TiO2 nanoparticles and used as photoanodes in dye-sensitized solar cells. Due to the plasmonic effect of the modified electrode, the power conversion efficiency of the solar cell was improved from 2.83% to 3.62% with increment around 28% after incorporation of the 2 wt% of the silver nanoparticles. Maximum increases in open-circuit voltage (up to 12.1%) and in short-circuit current density (up to 10.7%) were observed.