Novel organic dye sensitizers containing fluorenyl and biphenyl moieties for solar cells

Acenaphthylene-Based Chromophores for Dye-Sensitized Solar Cells: Synthesis, Spectroscopic Properties, and Theoretical Calculations

A set of acenaphthylene dyes with arylethynyl π-bridges was tested for dye-sensitized solar cells (DSSCs). Crucial steps for the extension of the conjugated system from the acenaphylene core involved Sonogashira coupling reactions. Phenyl, thiophene, benzotriazole, and thieno-[3,2-b]thiophene moieties were employed to extend the conjugation of the π-bridges. The systems were characterized by cyclic voltammetry and by UV-vis absorption and emission. The spectroscopic characterization showed that the last three bridges resulted in red-shifted absorption and emission spectra relative to the parent phenyl-bridged compound, in accordance with TD-DFT calculations. The phenylethynyl derivative 6a achieved a conversion efficiency of 2.51% with Voc, Jsc, and FF values of 0.365 V, 13.32 mA/cm2, and 0.52, respectively. The efficiency of this compound improved to 3.15% with the addition of CDCA (10 mM), representing the best efficiency result in this study. The overall conversion efficiency of the other aryl derivatives 6b-d proved to be significantly inferior (14-40%) to that of 6a due to a significant decrease of Jsc.

Influence of the auxiliary acceptor and π-bridge in triarylamine dyes on dye-sensitized solar cells

Four new dyes based on triarylamine donors with different π-bridges have been synthesized and showed the best overall conversion efficiency η of 7.92% (that of N719 dye was 8.53% under the same conditions).

Novel indeno[2,1-b]carbazole donor-based organic dyes for dye-sensitized solar cells

Four novel organic dyes based on indeno[2,1-b]carbazole donors were synthesized. CFT1 showed the best overall conversion efficiency η of 5.97% (J_SC = 12.34 mA cm⁻², V_OC = 0.71 V, and FF = 0.68) under simulated AM 1.5 irradiation (100 mW cm⁻²).