High performance quasi-solid-state dye-sensitized solar cells based on poly(lactic acid -co-glycolic acid)

Abstract

A stable quasi-solid-state dye-sensitized solar cell (DSC) with a novel amphiphilic polymer gel electrolyte (APGE) based on poly(lactic acid-co-glycolic acid) ( PLGA) is fabricated. The APGE could be readily prepared by a simple method at low temperature of 50 degrees C and exhibits a quasi-solid property, high conductivity, and long-term stability. The 20 and 40 wt% APGE-based DSCs show high photovoltaic conversion efficiency of 7.5 and 7.4%, respectively, under AM 1.5 simulated sunlight, which is comparable to the liquid electrolyte-based DSC with the efficiency of 7.6%. The 40 wt% APGE-based DSC maintains 95% of the initial performance after 60 days in practical conditions. It is also noteworthy that the APGE endows with higher short-circuit current density than the liquid electrolyte. Different natures of the APGE from the typical polymer gel electrolytes have been elucidated by the I-V measurements, electrochemical impedance spectroscopy, electrophoretic measurements, and transmission electron microscopy. (C) 2011 Elsevier B.V. All rights reserved.