title: Benzimidazole/Pyridoimidazole-Based Organic Sensitizers for High-Performance Dye-Sensitized Solar Cells.
abstract: A new series of benzimidazole (BIm)-based dyes (SC32 and SC33) and pyridoimidazole-(PIm) based dyes (SC35, SC36N and SC36) were synthesized as sensitizers for dye-sensitized solar cells (DSSCs). The N-substituent and C-substituent at the BIm and PIm cores were found to be the dominating factor in determining the electronic properties of the dyes and their DSSCs performance. The efficiency of BIm-based dyes (SC35 and SC36) was found to be higher than that of the PIm-based dyes (SC32 and SC33) due to better light harvesting. The C-substituents in SC36, a 4-hexylloxybenzene and a hexyl chain, are beneficial to dark current suppression, and hence SC36 achieves the best efficiency of 7.38 % (≈85 % of N719). The two BIm dyes have better cell efficiencies than their congeners with a bithiophene entity between the BIm and the anchor due to better light harvesting of the former.
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei, Taiwan.
authors.forename: Sumit
authors.initials: S
authors.lastname: Chaurasia
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei, Taiwan.
authors.forename: Chun-Ting
authors.initials: CT
authors.lastname: Li
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei, Taiwan.|Taiwan International Graduate Program (TIGP), Sustainable Chemical Science and Technology (SCST), Academia Sinica, Taipei, Taiwan.|Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan.|Department of Chemistry, Mekelle University, Tigray, Ethiopia.
authors.forename: Mulu Berhe
authors.initials: MB
authors.lastname: Desta
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei, Taiwan.
authors.forename: Jen-Shyang
authors.initials: JS
authors.lastname: Ni
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei, Taiwan.
authors.forename: Jiann T
authors.initials: JT
authors.lastname: Lin
keywords: benzimidazole derivatives; charge transfer; donor-acceptor systems; dye-sensitized solar cells; metal-free sensitizers