Quasi-Solid-State Dye-Sensitized Solar Cell with Ionic Gel Electrolytes By Semifluorinated Alkoxy Benzene Derivative

Abstract

Quasi-solid-state dye-sensitized solar cells (QS-DSSCs) have rapidly become an important research orientation in electronic vehicles. Especially, ionic liquid gel electrolytes (ILGEs) solidified by low molecular mass organogelators (LMOGs) can effectively possess higher ionic conductivity and good pore filling.1 Based on the advantage of ILGEs, we present here a kind of LMOGs (compounds 1(n)) by semifluorinated benzene derivatives. ILGEs formed by compounds 1(n) with different ionic liquids can divide two parts. One is with the representative [BMIM] posion-based ionic liquids (ILs), such as [BMIM] [I], [BMIM] [BF4], [BMIM] [FSA] and [BMIM] [TFSA]. Another one is with the representative [TFSA] anion-based ILs, such as [DEME] [TFSA], [EMIM] [TFSA], [TMPA] [TFSA], [AAIM] [TFSA] and [P13] [TFSA]. The minimum gelation concentrations in weight percent were determined at concentrations ranging from 5% to 1% in a heating-cooling cycle by the “stable to inversion in a test tube” method. The thermal properties of ILGEs which exactly is the effect of the concentration on the gel-sol phase transition temperatures (T gel) upon heating were examined. The ionic conductivity (σ) of ILGEs which is an important property for ILGEs was also examined. Compared with the data of ionic conductivities which has been reported in literature, it was found that the ionic conductivities in gel state were similar with ionic conductivities in liquid state. The conductivities of ILGEs with different concentrations of LMOGs were also analyzed. The diffusion of redox couple (I3 - and I-) ions in the ILGEs is an important factor for DSSCs property.2 In order to analyze the behavior of in I3 - and I- the ILGEs, linear sweep voltammetry studies were performed at a scan rate of 1.0 mVs-1 at room temperature. The performance of [BMIM] [I] was different with others. It maybe that ionic liquid of [BMIM] [I] contains anion of I- by itself. Reference 1. (a) Wang, P.; Zakeeruddin, S. M.; Comte, P.; Exnar, I.; Grätzel, M. Gelation of ionic liquid-based electrolytes with silica nanoparticles for quasi-solid-state dye-sensitized solar cells. Journal of the American Chemical Society 2003, 125 (5), 1166-1167; (b) Tao, L.; Huo, Z.; Ding, Y.; Li, Y.; Dai, S.; Wang, L.; Zhu, J.; Pan, X.; Zhang, B.; Yao, J. High-efficiency and stable quasi-solid-state dye-sensitized solar cell based on low molecular mass organogelator electrolyte. Journal of Materials Chemistry A 2015, 3 (5), 2344-2352. 2. Yoon, J.; ki Kang, D.; Won, J.; Park, J.-Y.; Kang, Y. S. Dye-sensitized solar cells using ion-gel electrolytes for long-term stability. Journal of Power Sources 2012, 201, 395-401.