Polymethyl acrylate-polyvinyl acetate blend polymer electrolytes for application in dye sensitized solar cell / Wan Amisha Adhwa Wan Azmar

The objective of this work is to study poly(methyl acylate)- poly(vinyl acetate) (PMA-PVAc) blend polymer electrolytes incorporated with tetrapropyl ammonium iodide (TPAI), 1-butyl-3-methylimidazolium iodide (BMII) and ethylene carbonate (EC) for the application in dye sensitized solar cells (DSSCs). The conductivity of the single polymer electrolyte was optimized by varying the concentration of TPAI. PMA show higher conductivity than PVAc. PMA/PVAc blends are miscible as indicated by dilute solution viscometry (DSV) and different scanning calorimetry (DSC). The highest conductivities achieved for PMA-TPAI and PVAc-TPAI system are 2.6

10-11 and 1.4
10-11 S cm-1, respectively. The polymer blend electrolyte with the composition WPVAc = 0.1 and WTPAI =0.2 shows the highest conductivity of 4.97 ×10-11 Scm-1. Then, BMII were introduced to the optimized system. The conductivity is found to increase up to 1.37× 10-9 Scm-1 with WBMII = 0.5. The DSSC fabricated using the highest conductiviting sample exibits the highest efficiency of 4.62 %. In the forth system, the mass fraction of EC, WEC was varied while the masses of the other components were kept constant in order to study the dependence of dye-sensitized solar cell (DSSC) performance on EC concentration. Incorporation of EC in PMA/PVAc-TPAI-BMII has enhanced the efficiency of the DSSC. The efficiency enhancement is due to the increase in short circuit current density, Jsc, arising from the conductivity enhancement brought about by the EC. A DSSC with TPAI-BMII-EC liquid electrolyte was fabricated and its photovoltaic and stability performance were investigated and compared with DSSC with PMA/PVAc-TPAI-BMII-EC gel electrolyte. PMA/PVAc decreases the Jsc from 27.87 to 22.91 mA cm-2 and efficiency, η from 12.28 to 9.67 %. Linear sweep voltammetry studies reveal that PMA/PVAc decreases the ion motion in the electrolyte. Although PMA/PVAc deteriorates the performance of DSSC, but it improves the stability performance of DSSC by suppressing the recombination loss as evidenced from the increase in charge transfer resistance at the TiO2 electrode and longer electron recombination lifetime calculated from EIS study.