Complexation of polyaniline and graphene for efficient counter electrodes in dye-sensitized solar cells: Enhanced charge transfer ability

With an aim of significantly enhancing charge-transfer ability of counter electrodes and therefore photovoltaic performances of dye-sensitized solar cells (DSSCs), here we pioneerly report the complexation of polyaniline (PANi) and graphene as well as their employment as counter electrodes (CEs) in efficient DSSCs. Owing to the covalent bond between PANi (N atoms) and graphene (C atoms), charge transfer kinetics is dramatically elevated, which can be confirmed by the enhancement on electrocatalytic activity toward triiodides and a decrease in charge-transfer resistance. A power conversion efficiency of 7.70% is determined from DSSC using PANi−8 wt‰ graphene complex CE in comparison with 6.40% from pure PANi CE-based DSSC. The high conversion efficiency, facile charge-transfer in combination with simple preparation, relatively low cost, and scalability demonstrates the potential use of PANi−graphene complexes in robust DSSCs. [Display omitted] •Aniline–graphene complexes were synthesized by a reflux technique.•PANi–graphene complex CEs were electro-polymerized by a CV approach.•Covalent bond between PANi and graphene can accelerate the charge transfer between them.•A conversion efficiency of 7.70% was obtained from PANi–8 wt‰ graphene complex CE-based DSSC.