Efficient organic dyes containing dibenzo heterocycles as conjugated linker part for dye-sensitized solar cells

Six new organic dyes, TBS1–TBS6, have been synthesized and characterized by optical, electrochemical, and theoretical studies. Among these dyes, DSSCs based on a dye containing N-hexylcarbazole and furan moieties (TBS4) showed the best performance, with light-to-electricity conversion efficiency up to 5.91% under AM 1.5 solar simulator, much higher than the reference dye TPS (4.24%). The high Voc contributed to the good performance for TBS4, which may be ascribed to the combined effects of twisted structure and hexyl chain. Additionally, for TBS4 based DSSCs, under optimized conditions, the light-to-electricity conversion efficiency was enhanced up to 7.09%. The results suggest that dibenzo heterocycles containing dyes are promising candidates for application in DSSCs.