New D–π-A system dye based on dithienosilole and carbazole: Synthesis, photo-electrochemical properties and dye-sensitized solar cell performance

Abstract

• A dual π-conjugation dye based on dithioensilole, carbazole was designed and synthesized. • The incorporation of dithioensilole and ethynyl lowered its LUMO level and energy gap. • DSSC sensitized by the dye possessed a power conversation efficiency of 4.80%. New donor–linker–acceptor pattern organic dye containing a dithienosilole unit as a π-conjugated system, a carbazole moiety as an electron donor, and a cyanoacrylic acid unit as an electron acceptor was synthesized for application in dye-sensitized solar cell ( DSSC ). Its photophysical and electrochemical properties were investigated, the dithienosilole unit could dramatically lower the lowest unoccupied molecular orbital ( LUMO ) level and energy gap. Its performances as sensitizers in solar cells were measured, and possessed a power conversion efficiency of 4.80%.