A Comparative Study of Plasmonic Dye-Sensitized Solar Cells Utilizing Dielectric Shell Coated and Uncoated Au nanoparticles

This article focuses on the plasmonic effect of gold nanoparticles incorporated in mesoporous TiO
₂
photoanode for high efficiency dye-sensitized solar cells (DSSC). We have adopted a facile TiCl
₄
posttreatment process for coating a thin TiO
₂
shell over the gold nanoparticles. The device without TiCl
₄
treatment and containing bare or uncoated gold nanoparticles exhibits a drop in efficiency compared to the control device. The cells fabricated with gold nanoparticles and posttreated with TiCl
₄
show higher efficiencies than the control device. The improvement in efficiency is attributed to a higher value of photocurrent in the plasmonic devices arising due to the near-field enhancement effects. The TiCl
₄
treated plasmonic cell provides a short-circuit current density (J
_SC
) of 12.90 mA/cm
²
compared to 10.76 mA/cm
²
obtained from the control device. The overall power conversion efficiency is enhanced from 4.81% for the control DSSC to 5.71% for the TiCl
₄
treated plasmonic DSSC. This plasmonic DSSC has also been compared with another type of plasmonic DSSC containing Au@SiO
₂
core-shell nanoparticles. The photovoltaic performances of the two types of plasmonic DSSCs utilizing dielectric shell coated Au NPs are found to be similar, indicating the suitability of the TiCl
₄
treatment for facile and reproducible fabrication of plasmonic solar cells.