Conductivity behaviour in novel quasi-solid-state electrolyte based on polyacrylonitrile and tetrahexylammonium iodide intended for dye sensitized solar cells

The  conduction  of  iodide  ions  in  gel  polymer  electrolytes and the performance  of dye  sensitized  solar cells  containing such an electrolyte can be enhanced by incorporating  a  salt  having  a  bulky  cation.  In  this  work,  polyacrylonitrile  (PAN)  and  Hex4N+I¯  based  gel  electrolytes  with  ethylene  carbonate  and  propylene  carbonate  as  plasticizers  have  been  studied. The variation of conductivity and molar conductivity  with salt concentration has been discussed in order to understand  the mechanism of iodide ion conductivity in this system. Out  of the various compositions studied, the electrolyte containing  120 % salt with respect to weight of PAN showed the highest  conductivity,  2.0  ×  10-3 Scm−1 at  25 °C  and  a  glass  transition  at  -  102.3  °C.  The  electrolytes  exhibit  predominantly  ionic  behaviour and because of the bulky cation a negligible cationic  transport is shown. A quasi-solid-state dye sensitized solar cell  was  fabricated  employing  the  optimized  gel  electrolyte. This  cell  showed  an  energy  conversion  efficiency  of  3.1 % and  a  short circuit current density  of    8.1 mAcm-2 under irradiation of 1000 Wm-2.

J.Natn.Sci.Foundation Sri Lanka 2013 41 (3): 175-184

DOI: http://dx.doi.org/10.4038/jnsfsr.v41i3.6056