Binder-free MWCNT/TiO2 multilayer nanocomposite as an efficient thin interfacial layer for photoanode of dye sensitized solar cell

Abstract

Multiwalled carbon nanotube/TiO2 multilayer nanocomposite was successfully deposited on the fluorine-doped tin oxide (FTO) glass via layer-by-layer assembly technique to modify interfacial contact between the FTO surface and nanocrystalline TiO2 layer as well as carbon nanotube/TiO2 contacts in photoanode of dye sensitized solar cell. Using this approach, binder-free interfacial thin film was developed with nonagglomerated, well-dispersed MWCNTs on FTO and into TiO2 matrix and with maximum covering of TiO2 nanoparticles on MWCNTs. Introduction of MWCNTs/TiO2 interfacial layer into the TiO2 photoanode increased short circuit current density (Jsc) from 11.90 to 17.25mA/cm2 and open circuit voltage (Voc) from 730mV to 755mV, whereas there was no notable change in the fill factor (FF). Consequently, power conversion efficiency (η) was enhanced from 5.32% to 7.53%, yielding a 41.5% enhancement. The results suggest that our simple strategy can integrate reduction of back electron reaction at FTO/TiO2 interface with the effective charge transport ability of carbon nanotubes and possessing high surface area for efficient dye loading.