Dimeric dithiafulvene sensitizers involving a 1,3,4-oxadiazole as auxiliary acceptor and pyridine as electron-withdrawing anchoring group for efficient dye sensitized solar cells

Abstract Two dimeric dithiafulvene based sensitizers D-DTFPy6 and D-DTFPy7 with pyridine as electron-withdrawing anchoring group were synthesized, and the effect of the involving of 1,3,4-oxadiazole as auxiliary acceptor on bulk properties, such as photophysical and photochemical properties were investigated. Comparing with D-DTFPy6, the1,3,4-oxadiazole auxiliary acceptor based D-DTFPy7 exhibits red-shift of the absorption. As a result, dye sensitized solar cells based on D-DTFPy7 yielding the highest power conversion efficiency of 6.56% alongside with a short-circuit current density of 14.92 mA cm−2 and an open-circuit voltage of 708 mV, which is 1.17-, 1.1-, and 1.03-fold higher than those of its non-auxiliary acceptor counterpart D-DTFPy6 based cells, respectively.