Preparation and characterization of quasi-solid-state electrolytes using a brominated poly(2,6-dimethyl-1,4-phenylene oxide) electrospun nanofiber mat for dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) are prepared with quasi-solid-state electrolytes by employing electrospun nanofiber mats. Here, we investigated the effects of a brominated poly(phenylene oxide) (BPPO) electrospun nanofiber mat used as a non-fluorinated polymer backbone in DSSCs. It was found that BPPO, which contains ether and bromine functional groups of non-bonding electrons, acts as a Lewis base. This Lewis basicity not only negatively shifted the flat band, but also coordinated Li ions in the electrolyte. As a result, by introducing a quasi-solid-state electrolyte, the open circuit voltage increased by 50 mV and the photon-to-current efficiency was comparable to a conventional liquid electrolyte. Furthermore, the quasi-solid-state DSSCs exhibited enhanced long-term stability, maintaining 97% of initial efficiency after 7 d under a mild acceleration condition at 50 °C.