Panchromatic light harvesting by N719 with a porphyrin molecule for high-performance dye-sensitized solar cells

We report efficient panchromatic light harvesting by co-adsorption of a porphyrin molecule and N719 in dye-sensitized solar cells. The cosensitized device shows a considerably enhanced power conversion efficiency of 8.89%, while those individually sensitized by porphyrin and N719 display efficiencies of 7.21% and 8.02%, respectively. The porphyrin-sensitized device shows strong photocurrent generation in the Soret and Qbands, while N719 shows efficient spectral response in the 500-600 nm range; the combination of these two kinds of dye molecules displays a strong spectral response in the full-colour region. Mechanistic investigations are carried out by various spectral and electrochemical characterizations.