Azafluorene Ornamented Thiazine Based Novel Fused Heterocyclic Organic Dyes for Competent Molecular Photovoltaics

Abstract Described herein is a series of azafluorene ornamented thiazine based novel fused heterocyclic organic dyes TBCPCA-1 , TBCPCA-2 , TBTCPCA-1 and TBTCPCA-2 . Nanocrystalline titania based DSSC performance along with photophysical/electrochemical behaviors of the aforementioned dyes have been examined. Utilizing computational approach, distribution of electrons within the molecules has been explored. The devices possessing the novel fused dyes TBCPCA-1 , TBCPCA-2 , TBTCPCA-1 and TBTCPCA-2 as sensitizers exhibited overall power conversion efficiency range between 6.17 ± 0.4 and 7.97 ± 0.3%. The novel fused heterocyclic organic dyes featuring di- tert -butylazafluorene structural motif such as TBCPCA-1 and TBCPCA-2 exhibit higher power conversion efficiency than the ones carrying sterically congested tetra- tert -butyl-tri(azafluorene) scaffold viz., TBTCPCA-1 and TBTCPCA-2 . Amongst the devices fabricated with the utilization of novel heterocyclic dyes as sensitizers, the device possessing the dye TBCPCA-2 as sensitizer displayed the highest power conversion efficiency of 7.97 ± 0.3% along with a V oc of 745 ± 0.6 mV, a J sc of 16.92 ± 0.3 mA.cm −2 and a ff of 0.67 ± 0.003.