Efficiency enhancement in plasmonic dye-sensitized solar cells with TiO2 photoanodes incorporating gold and silver nanoparticles

Abstract

Plasmonic dye-sensitized solar cells (DSSCs) were fabricated using TiO2 photoanodes incorporating gold nanoparticles (AuNPs) with 15–20-nm size and silver nanoparticles (AgNPs) with 40–60-nm size. These were characterized by UV–Vis spectroscopy, J–V characteristic, IPCE spectroscopy, EIS analysis and dark I–V measurements. Under the illumination of 100 mW cm−2 (AM 1.5), the efficiency of the reference DSSC without Au and Ag NPs in TiO2 was 5.12 %, while the efficiencies of plasmonic DSSCs with TiO2:AuNP and TiO2:AgNP were 6.23 and 6.51 %, respectively, representing an efficiency enhancement by 21.6 % for AuNPs and 27 % for AgNPs. The increased efficiencies of the two plasmonic DSSCs appear to be due to the increased short-circuit photocurrent density by enhanced light harvesting caused by the localized surface plasmon resonance effect. The IPCE spectra of the two plasmonic DSSCs suggest the narrowing of the energy band gap of TiO2 due to the presence of Au and Ag nanoparticles.