Plasmon-enhanced photocurrent in dye-sensitized solar cells

Plasmonic structures of FTO/TiO2/NPs-Ag and FTO/NPs-Ag/TiO2 electrodes were fabricated by sputter technology and the sol–gel & spin coating procedure. These electrodes with similar optical absorptions in the visible region enhanced by the surface plasmon resonance of silver nanoparticles have different photovoltaic properties, revealing that the significant design can be used to identify the favorably enhanced direction of plasmonic structure resulting from plasmonic scattering to trap light which confines light within the active TiO2 layer to promote dye absorption in dye-sensitized solar cells (DSSCs). In the FTO/TiO2/NPs-Ag, a 60% enhancement in photocurrent and an improvement in photovoltage were observed and the increased incident photon-to-photocurrent efficiency (IPCE) was consistent with the enhanced absorption spectrum. However, the photovoltaic properties of the FTO/NPs-Ag/TiO2 were similar to those of the standard electrode. This concept is potentially applicable to new kinds of solar cells.

► FTO/TiO2/NPs-Ag and FTO/NPs-Ag/TiO2 electrodes have similar optical characteristics.
► The photocurrent of one is higher than the other compared to standard electrode.
► Extra photoelectrons are driven toward collecting FTO by surface plasmon resonance.
► The favorably enhanced direction of excited plasmon improves photovoltaics property.