ACID-BASE EQUILIBRIA OF ORGANIC DYES SUITABLE FOR DYE-SENSITIZED SOLAR CELLS

Abstract

We have successfully synthesized and characterized the dyes, possess moderate thermal stability - and useful in dye sensitized solar cell. The properties of dyes are investigated with different approaches. As the solvent polarity affects the absorption properties of the dye therefore we performed solvatochromism studies. The absorption maxima also influenced by the protonated and deprotonated state of sensitizer subsequently we studied acid-base equilibrium for the conformation of the state of the dye in a particular solvent. An electrochemical study furnishes the information about the HOMO and LUMO of the dye and the band gap, so that we can assign the facilitation of electron transfer in DSSCs. We also verified the Beer-Lambert law, the extinction coefficient was in good agreement with the experimental value. Finally we premeditated the effect of pH on different dye and calculated the pKa value for these dyes because we want to know about the pH at which the dye absorb at maximum wavelength and by the pKa value we can conclude that in a particular solvent it will be protonated or deprotonated..