Molecular Design of Anthracene-Bridged Metal-Free Organic Dyes for Efficient Dye-Sensitized Solar Cells

Metal-free org. dyes bridged by anthracene-contg. π-conjugations were designed and synthesized as new chromophores for dye-sensitized solar cells (DSSCs). Studies on the relation between the dye structure, photophys. properties, electrochem. properties and performances of the DSSCs are described. With the introduction of the anthracene moiety, together with a triple bond for the fine-tuning of mol. planar configurations and to broaden absorption spectra, the Jsc and Voc of DSSCs improved. The improvement of Jsc is attributed to a broader absorption spectra of the dyes with the anthracene moiety. EIS anal. reveals that the anthracene moiety suppresses charge recombination arising from electrons in TiO2 films with I3- ions in the electrolyte, thus improving Voc. From optimized mol. structures and DSSC test conditions, the dye TC501 shows a prominent solar energy conversion efficiency up to 7.03% (Jsc = 12.96 mA/cm2, VOC = 720 mV, ff = 0.753) under simulated AM 1.5 irradn. (100 mW/cm2).