Self‐Assembled Liquid‐Crystalline Ion Conductors in Dye‐Sensitized Solar Cells: Effects of Molecular Sensitizers on Their Performance. Issue 6 (26th April 2017)

• Record Type: Journal Article
• Authors: Högberg, Daniel; Soberats, Bartolome; Yoshio, Masafumi; Mizumura, Yurika; Uchida, Satoshi; Kloo, Lars; Segawa, Hiroshi; Kato, Takashi
• Is Part Of: ChemPlusChem. Volume 82:Issue 6(2017)
• Page Start: 834
• Page End: 840
• Publication Date: 2017-04-26
• Subjects: electrolytes -- liquid crystals -- nanostructures -- self-assembly -- solar cells; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cplu.201700099
• Languages: English
• ISSNs: 2192-6506

Abstract

Abstract: Dye‐sensitized solar cells employing nonvolatile liquid‐crystalline (LC) electrolytes that form nanostructures capable of efficient ion transport are reported. The LC electrolyte consists of a cyclic carbonate‐functionalized mesogen and an iodide‐based ionic liquid that nanosegregates into lamellar structures exhibiting over four times higher ion conductivities parallel to the layers than perpendicular to the layers. The self‐assembled ion pathways allow efficient ion transport in the semi‐solid LC state. When used together with organic dyes, DSSCs employing these LC electrolytes show higher power conversion efficiency (PCE) than metal–organic dyes. This behavior is not observed for devices containing standard liquid electrolytes. The higher PCEs of the LC‐based devices can be attributed to longer electron lifetimes ( τ ) and higher electron densities in the photoelectrodes. The high concentration of iodide ions in the nanostructured pathways of the LC electrolyte is thought to induce reductive quenching of the ruthenium‐based sensitizer, which competes with the electron injection process and lowers the τ and electron densities of the TiO2 . Abstract : Bright future : Nanostructured liquid crystals forming self‐assembled two‐dimensional ion‐transport pathways have been applied as electrolytes in dye‐sensitized solar cells (DSSCs; see figure). DSSCs based on these liquid‐crystalline (LC) electrolytes and organic dye sensitizers show more efficient energy conversion than LC‐DSSCs based on ruthenium metal–organic dyes.