A new porphyrin bearing a pyridinylethynyl group as sensitizer for dye sensitized solar cells

A novel porphyrin dye extended at one meso-position via an pyridinylethynyl group acting as anchoring group and three phenyl COOMe groups was synthesized and used as sensitizer for the fabrication of dye sensitized solar cells (DSSCs). The overall power conversion efficiencies (PCE) of DSSCs based on this porphyrin dye as sensitizer with and without CDCA coadsorbant are 3.36% and 4.56%, respectively. To improve the PCE of DSSC, we have incorporated Ag nanoparticles into the nano-porous TiO2 photoanode i.e. FTO/TiO2/Ag-NPs and found a enhancement up to 5.66%. The improved photovoltaic performance of the DSSCs with modified photoanode is attributed to the (i) the increased light harvesting efficiency due to the plasmon enhanced optical absorption induced by Ag nanoparticles, (ii) reduced back recombination process at TiO2/dye/electrolyte interface, (iii) improved electron lifetime, and (iv) formation of Schottky barrier at TiO2/NPs-Ag.