Morphological and electrochemical properties of carbon nanotubes-polymer composites electrolyte for dye sensitized solar cells

The novel and new carbon nanotube (CNTs) - polyacrylonitrile (PAN)/polymethyl methacrylate (PMMA) composite electrolytes was prepared by the thermal polymerization of acrylonitrile/ methyl methacrylate (MMA) with CNTs for solid-state dye sensitized solar cells (DSSCs). By the morphological and surface properties, the increased thickness of CNTs indicated the attachment of polymer (PAN or PMMA) molecules on the surface of CNTs. The strong interaction between CNT and polymer molecules resulted in the lowering of crystallinity which leads the high ionic conductivity of composite electrolytes. DSSCs fabricated with CNTs-PAN composite electrolytes achieved high conversion efficiency of 3.85% with an open circuit voltage (V_OC) of 0.57 V, short circuit current density (J_SC) of 10.9 mA/cm² and fill factor of 63.6%, whereas DSSC with CNT-PMMA showed lower conversion efficiency of 2.9%. The enhanced photovoltaic performance in DSSC with CNTs-PAN composite electrolyte resulted from the increased amorphicity and ionic conductivity of composite electrolytes.