Modification on C219 by coumarin donor toward efficient sensitizer for dye sensitized solar cells: A theoretical study

Abstract Dye sensitized solar cell sensitized by organic dye C219 (Chem. Mater, 2010 , 22, 1915–1925) has reached the record efficiency ( η ) of 10.1% with comparable short-circuit current density ( J sc ) but relatively lower open-circuit photovoltage ( V oc ) as compared to that of ruthenium-based cells. With the motivation of further enhancing V oc , we designed three dyes 1–3 with different electron donors, i.e. carbazole, indoline and coumarin. Based on the theoretical analysis of the conduction band energy shift of TiO 2 , electron injection rate and electron lifetime, the three designed dyes all show larger V oc than that of C219 . On the other hand, 3 should also have larger J sc compared with that of C219 due to its red-shifted spectrum and higher light harvesting efficiency. Thus we expect that the cell sensitized by 3 could exhibit both larger V oc and J sc in comparison to the champion C219 -based cells.