Novel chemically cross-linked solid state electrolyte for dye-sensitized solar cells

Poly(vinylpyridine-co-ethylene glycol methyl ether methacrylate) (P(VP-co-MEOMA)) and alpha,omega-diiodo poly(ethylene oxide-co-propylene oxide) (I[(EO)(0.8)-co-(PO)(0.2)](y)I) were synthesized and used as chemically cross-linked precursors of the electrolyte for dye-sensitized solar cells. Meanwhile, alpha-iodo poly(ethylene oxide-co-propylene oxide) methyl ether (CH3O[(EO)(0.8)-co-(PO)(0.2)](x)I) was synthesized and added into the electrolyte as an internal plasticizer. Novel polymer electrolyte resulting from chemically cross-linked precursors was obtained by the quaterisation at 90 degrees C for 30 min. The characteristics for this kind of electrolyte were investigated by means of ionic conductivity, thermogravimetric and photocurrent-voltage. The ambient ionic conductivity was significantly enhanced to 2.3 x 10(-4) S cm(-1) after introducing plasticizer, modified-ionic liquid. The weight loss of the solid state electrolyte at 200 degrees C was 1.8%, and its decomposition temperature was 287 degrees C. Solid state dye-sensitized solar cell based on chemically cross-linked electrolyte presented an overall conversion efficiency of 2.35% under AM1.5 irradiation (100 mW cm(-2)). The as-fabricated device maintained 88% of its initial performance at room temperature even without sealing for 30 days, showing a good stability. (C) 2010 Elsevier Ltd. All rights reserved.