Spectral sensitization of TiO2 by new hemicyanine dyes in dye solar cell yielding enhanced photovoltage: Probing chain length effect on performance

New hemicyanine dyes having indole nucleus with different alkyl chain length were synthesized and characterized using 1H NMR and mass spectroscopy. These dyes were used to sensitize the TiO2 film in dye sensitized solar cell. Nanocrystalline dye solar cells were fabricated and characterized using various electrochemical techniques. It has been found that the alkyl chain length present in the dye molecules greatly affects the overall performance of dye solar cell. Molecules having longer alkyl chain are having better sensitizers which enhance Voc to significant extent. Chain length dependent performance was further investigated using Tafel polarization and impedance method. Hemicyanine dye having hexyl chain has outperformed by attaining 2.9% solar to electricity conversion efficiency.

New hemicyanine dyes based on indolenine moiety were utilized as light harvesting materials in dye sensitized solar cell. Chain lengths of the molecules were varied in order to study its effect of chain length on the performance of DSSC. Electron transfer kinetic of the solar cell was studied and it was found that the chain length changes the electron transfer kinetic. We have achieved remarkable photovoltage and overall performance of DSSC.Figure optionsDownload as PowerPoint slideHighlights
► New hemicyanine dyes based on indolenine moiety were utilized as light harvesting materials in dye sensitized solar cell.
► Chain lengths of the molecules were varied in order to study its effect of chain length on the performance of DSSC.
► Electron transfer kinetic of the solar cell was studied and it was found that the chain length changes the electron transfer kinetic.