Novel organic dyes with pyrene auxiliary donor and naphthalimide auxiliary acceptor for dye sensitized solar cell applications

Abstract

The research work entitled NOVEL ORGANIC DYES WITH PYRENE AUXILLARY DONOR AND NAPHTHALIMIDE AUXILIARY ACCEPTOR FOR DYE SENSITIZED SOLAR CELL APPLICATIONS presented in the thesis highlights the synthesis of metal free organic dyes their photophysical and photovoltaic properties for the applications in dye sensitized solar cells and cell imaging newlineChapter 1 gives a brief description about history of solar cells different types of solar cells with their power conversion efficiencies addressed The photovoltaic parameters pertaining to DSSC for evaluating the power conversion efficiency have been discussed The advantages of metalfree dyes over metalbased dyes have been mentioned Various metalfree dyes based on phenothaizine and triphenylamine have been listed based on their molecular engineering of donor linker and acceptor part and their power conversion efficiency values were compared Biocompatibility as assessed by MTT assay and cell imaging is also discussed newlineChapter 2 describes the rational designing of six metalfree organic dyes based on phenothiazine with pyrene moiety as a part of the donor and cyanoacetic acid as acceptor for the application in dye sensitized soar cells This structural framework involving nonplanar phenothiazine donor is expected to prevent aggregation and the hydrophobic pyrene as auxiliary donor is expected to retard recombination of the injected electron with the electrolyte and enhance the photocurrent The presence of pyrene and alkynyl moieties ensures both hydrophobic periphery and extended conjugation therefore enhancing the absorption ability resulting in good photovoltaic performance The absorption spectra of the dyes with carboxylic acid end group showed broadening and red shift on the TiO2 surface when compared with the corresponding spectra in solution thus favouring enhanced photovoltaic efficiency The dyes with cyano as the anchoring moiety showed blue shift in their absorption spectra on the TiO2 surface Further the dye loading was also reduced due to poor anchoring ability of t