title: Monobenzoporphyrins as Sensitizers for Dye-Sensitized Solar Cells: Observation of Significant Spacer-Group Effect.
abstract: A series of monobenzoporphyrins (WH1-WH4) bearing different conjugated spacer groups were designed and synthesized as sensitizers for dye-sensitized solar cells. Although a phenyl spacer only has a minimal impact on the absorption bands of the monobenzoporphyrin, an ethynylphenyl (WH3) or a vinyl (WH4) spacer redshifts and broadens the absorption bands of the dyes to result in much enhanced light-harvesting ability. Dye-sensitized solar cells based on these monobenzoporphyrin dyes displayed remarkable differences in power conversion efficiencies (PCEs). The monobenzoporphyrin bearing no spacer (WH1) resulted in a PCE of only 0.5 %; in contrast, the monobenzoporphyrin bearing vinyl spacers (WH4) achieved a PCE of 5.2 %. The high efficiency of the WH4 cell is attributed to the higher light-harvesting ability, the lesser extent of aggregation on the TiO2 surface, and the more favorable electron-density distributions of the HOMO and LUMO for electron injection and collection. This work demonstrates the exceptional tunability of benzoporphyrins as sensitizers for dye-sensitized solar cells.
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA.
authors.forename: R G Waruna
authors.initials: RG
authors.lastname: Jinadasa
authors.affiliation: Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, OH, 45056, USA.
authors.forename: Bihong
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schmitz
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA.
authors.forename: Siddhartha
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, OH, 45056, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Kerr
authors.affiliation: Department of Chemistry and Biochemistry, Miami University, Oxford, OH, 45056, USA. wangh3@miamioh.edu.
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
mesh_terms: D004396:Coloring Agents / Q000737:chemistry*; D011211:Electric Power Supplies; D008958:Models, Molecular; D008968:Molecular Conformation; D055620:Optical Phenomena; D011166:Porphyrins / Q000737:chemistry*; D012993:Solar Energy; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D011166:Porphyrins; C009495:titanium dioxide; D014025:Titanium
keywords: dyes; electrochemistry; energy conversion; porphyrinoids; substituent effects