Effect of Thiophene π-Conjugation Spacers on the Performance of Photosensitized Dyes Having Trifluoromethylthiazole-5-carboxylic Acid as an Acceptor-anchor Moiety

Abstract Novel photosensitized trifluoromethylthiazole-5-carboxylic acid dyes having different numbers of thiophene π-conjugation spacers (MCL15, MCL17, and MCL19) and a benzodithiophene spacer with long alkyl side chains (MCL40) are synthesized. The resulting extension of the π-conjugation system leads to redshift in the absorption wavelength. The long alkyl side chains of benzodithiophene cause a dispersed aggregation effect; therefore, the co-adsorbent becomes unnecessary for dye-sensitized solar cell (DSSC) fabrication. The DSSCs fabricated using these dyes exhibit increased conversion efficiency compared with those without a thiophene unit (MCL05).