Solar Energy Materials and Solar Cells, Vol.95, No.8, 1990-1995, 2011
Enhanced performance of a quasi-solid-state dye-sensitized solar cell with aluminum nitride in its gel polymer electrolyte
The effects of incorporation of aluminum nitride (AIN) in the gel polymer electrolyte (GPE) of a quasisolid-state dye-sensitized solar cell (DSSC) were studied in terms of performance of the cell. The electrolyte, consisting of lithium iodide (Lil), iodine (12), and 4-tert-butylpyridine (TBP) in 3-methoxypropionitrile (MPN), was solidified with poly(vinyidene fluoride-co-hexafluoro propylene) (PVDF-HFP). The 0.05, 0.1, 0.3, and 0.5 wt% of AIN were added to the electrolyte for this study. XRD analysis showed a reduction of crystallinity in the polymer PVDF-HFP for all the additions of AIN. The DSSC fabricated with a GPE containing 0.1 wt% AIN showed a short-circuit current density (J(sc)) and power-conversion efficiency (eta) of 12.92 +/- 0.54 mA/cm(2) and 5.27 +/- 0.23%, respectively, at 100 mW/cm(2) illumination, in contrast to the corresponding values of 11.52 +/- 0.21 mA/cm(2) and 4.75 +/- 0.08% for a cell without AIN. The increases both in J(sc) and in eta of the promoted DSSC are attributed to the higher apparent diffusion coefficient of I- in its electrolyte (3.52 x 10(-6) cm(2)/s), compared to that in the electrolyte without AIN of a DSSC (2.97 x 10(-6) cm(2)/s). At-rest stability of the quasi-solid-state DSSC with 0.1 wt% of AIN was found to decrease hardly by 5% and 7% at room temperature and at 40 degrees C, respectively, after 1000 h duration. The DSSC with a liquid electrolyte showed a decrease of about 40% at room temperature, while it virtually lost its performance in about 150 h at 40 degrees C. Explanations are further substantiated by means of electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and by porosity measurements. (C) 2010 Elsevier B.V. All rights reserved.