Photocurrent enhancement by surface plasmon resonance of gold nanoparticles in spray deposited large area dye sensitized solar cells

• Preparation of TiO2 and TiO2–Au films with a large area of ~ 7.5 cm2 by a spray technique
• An efficiency of ~ 4.5% achieved by the large area plasmonic DSSC
• Photocurrent enhancement due to SPR effects of gold NPs observed
• Comparison of the spray and conventional doctor blade methods in DSSC performance
• Demonstration of technological feasibility and versatility of a simple spray process

A facile method for fabricating large area TiO2 and TiO2–Au nanocomposite films for dye sensitized solar cells (DSSCs) is presented using a spray technique. Pre-synthesized gold nanoparticles (Au NPs) were sprayed together with the TiO2 NPs and composite films with brilliant coloration due to surface plasmon resonances of Au NPs were prepared. Composite films containing ~ 15 nm sized Au NPs exhibited enhanced absorption in the visible region of the electromagnetic spectrum. DSSCs with a large area of ~ 4.5 cm2 were fabricated and a photocurrent enhancement of ~ 10% was obtained for plasmonic DSSC containing 0.3 wt.% of ~ 15 nm Au NPs. Incident photon to current conversion efficiency data conclusively showed enhanced currents in the visible region of the polychromatic spectrum arising due to plasmon enhanced near-field effects of Au NPs around the absorbing dye molecules.