Synthesis, optical and electrochemical properties of pyridal[2,1,3] thiadiazole based organic dyes for dye sensitized solar cells

The asymmetric nature of pyridal[ 2,1,3] thiadiazole (PyT), allows the synthesis of two isomers, series SC-PyTNn (n = 1-4) and SC-NPyTn (n = 1-6), where the nitrogen atom of PyT is positioned closer to the arylamine donor and the anchoring group, respectively. PyT derivatives have significant bathochromic shift of the electronic absorption compared to their 2,1,3-benzothiadiazole congeners. The short-circuit photocurrent density, open-circuit voltage and fill factor of DSSCs using the dyes as the sensitizers are in the range of 0.68-9.47 mA/cm (2), 0.43-0.61 V and 0.59-0.72, respectively. SC-NPyTn (n = 1-6) exhibited higher cell efficiencies than SC-PyTNn (n = 1-4). Power conversion efficiency of up to 4.24% was observed for SC-NPyT3. (C) 2013 Elsevier B.V. All rights reserved.