title: Novel Ruthenium Sensitizers with a Phenothiazine Conjugated Bipyridyl Ligand for High-Efficiency Dye-Sensitized Solar Cells.
abstract: Two efficient ruthenium sensitizers with a phenothiazine-modified bipyridine as an ancillary ligand, coded SCZ-1 and SCZ-2, have been developed as dyes in dye-sensitized solar cells (DSSCs). Both sensitizers exhibit low-energy metal-to-ligand charge transfer (MLCT) bands centered at 539 nm with high molar extinction coefficients of 1.77 × 10(4) M(-1) cm(-1) for SCZ-1 and 1.66 × 10(4) M(-1) cm(-1) for SCZ-2, which are significantly higher than the corresponding value for the reference N719 (1.27 × 10(4) M(-1) cm(-1)), indicating that the light-harvesting capacity of ruthenium sensitizers can be reinforced by introducing phenothiazine moieties into the bipyridine ligand. Under AM 1.5G irradiation (100 mW cm(-2)), SCZ-1 and SCZ-2 sensitized DSSC devices show impressive power conversion efficiencies (PCE) up to 10.4% by using of iodide-based electrolytes, which exceeds that of N719 (9.9%) under the same conditions. Both of the open circuit voltage (VOC) and fill factor (FF) of SCZ-sensitized solar cells approximate to those of N719-sensitized cell. The relatively higher efficiencies of the SCZ-sensitized cells than that of N719-sensitized cell come from their higher short-circuit photocurrent density (JSC), which may be mainly attributed to the high absorption coefficient. The absorption spectrum and device efficiency of SCZ-1 are both quite close to those of SCZ-2, suggesting that the difference in alkyl chains on the N atom of phenothiazine is not a decisive factor in affecting the photovoltaic performance of dyes.
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: She
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Luoqiang
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Lan
authors.affiliation: College of Materials Science and Engineering, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Ruilin
authors.initials: R
authors.lastname: Wang
authors.affiliation: Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, and State Key Laboratory of Biotherapy, West China Medical School, Sichuan University , 29 Wangjiang Road, Chengdu 610064, China.
authors.forename: Jingsong
authors.initials: J
authors.lastname: You
keywords: dye-sensitized solar cell; high-efficiency; light-harvesting capacity; phenothiazine; ruthenium sensitizer