Synthesis of Organic Dyes with Linkers Between 9,9-Dimethylfluorenyl Terminal and α-Cyanoacrylic Acid Anchor, Effect of the Linkers on UV-Vis Absorption Spectra, and Photovoltaic Properties in Dye-Sensitized Solar Cells

Abstract

Six metal-free organic dyes having thiophene (1), benzene-thiophene (2), thiophene-benzene (3), thiophene-pyridine (4), thiophene-thiophene (5), and pyridine (6) linkers between 9,9-dimethylfluorenyl terminal group and <TEX>$\alpha$</TEX>-cyanoacrylic acid anchor were synthesized. Among them, organic dye 5 showed the longest <TEX>${\lambda}_{max}$</TEX> value (424 nm) in UV-Vis absorption spectrum, better incident monochromatic photon-to-current conversion efficiency (IPCE), highest short circuit photocurrent density (<TEX>$J_{SC},\;9.33\;mA^2/cm^2$</TEX>), and highest overall conversion efficiency (<TEX>$\eta$</TEX>, 3.91%).