Photocurrent enhancement in dye-sensitized photovoltaic devices with titania-graphene composite electrodes

摘要

Photovoltaic performance of dye-sensitized solar cell(DSC)devices based on a new titania-graphene paste has been investigated using Impedance Spectroscopy(IS)technique. The results provide key information about device performance, clarifying that photocurrent increment is not related to lower charge transfer resistance, neither with a downshift of the Fermi level of the graphene titania semiconductor. The DSC devices constructed using titania-graphene paste and graphene thin films reach higher photocurrent and therefore higher efficiency than devices made with a commercial paste due to extra photocurrent generation, because the titania-graphene paste presents higher light harvesting in the visible region of the solar spectra combined with large scatter effect than the commercial titania paste.