New banana shaped A-D-pi-D-A type organic dyes containing two anchoring groups for high performance dye-sensitized solar cells

摘要

Two new bent A-D-pi-D-A type organic dyes (MA-1 and MA-2) consisting of carbazole and phenothiazine moieties as electron donors with 2,1,3-benzothiadiazole as a pi-linker with two end-anchoring groups are designed, synthesized and tested in DSSCs. The photophysical and electrochemical properties of the dyes are investigated in detail. Incorporation of phenothiazine unit in MA-2 resulted in high HOMO level (0.62 V vs. NHE), with a red shift in absorption maxima and broadening of the absorption spectrum. Under standard global AM 1.5 solar conditions, the MA-2 sensitized solar cells exhibited a short circuit photocurrent density of 13.1 mA cm(-2), an open-circuit voltage of 0.73 V, a fill factor of 0.72, corresponding to an overall conversion efficiency of 6.87%. Such design and development of molecular dyes are useful for improving the overall efficiency of DSSCs. (C) 2016 Elsevier Ltd. All rights reserved.