| As a typical representative of third-generation photovoltaic devices, dye sensitized solar cell(DSSC) has been considered to be a new photovoltaic alternative to traditional silicon-based solar cells due to its simple procedure, low-cost, high efficient and environment-benign characteristic. DSSC is composed of transparent conductive glass, nono-Ti O2 photoanode adsorbed light sensitive dye, electrolyte containing redox couples, and counter electrode. Redox couple is an important electronic transport medium in the electrolyte, it has a decisive influence on the overall performance of DSSC. I3-/I- is the most investigated redox couple for now, although it has got a higher power conversion efficiency, some drawbacks, including the corrosion of the metal electrode, the absorption of I3-/I- in visible light region, still inhibit its industrial development. In addition, the traditional organic solvent based liquid electrolyte has a greatly restricted in the long-term stability of DSSC because the problem of electrolyte leakage and the evaporation of organic solvent.To solve these problems, we investigate the iodine-free redox couple and host-guest based supramolecular ionic liquid gel electrolyte. The main content is as follows:(1)Two kind of imidazolium functionalized TEMPO, mono-TEMPO and bis-TEMPO, was synthesized, and characterized by NMR and TGA. The prepared TE MPO based hybrid redox couple with PMII(1-propyl-3-methylimidazoliumiodide) has a higher redox potential, and has a negligible absorption in the visible region in contrast to I3 -/I- based redox that showed a strong absorption. The resultant device exhibited an overall power conversion efficiency of 8.8% under the simulated air mass 1.5 solar spectrum illumination at 100 m W cm-2.(2) An ionic liquid based supramolecular gel electrolyte was prepared through the host-guest interactions, the gel-to-sol phase transition temperature of the prepared supramolecular ionic liquid gel could be tuned by the ratio of host to guest, this gel electrolyte is more beneficial to the device fabricate. The DSSCs based supramolecular gel electrolyte showed a power conversion efficiency of 4.79% under the simulated air mass 1.5 solar spectrum illumination at 100 m W cm-2 and an excellent long-term stability. |
