Cerium doped TiO2 photoanode for an efficient quasi-solid state dye sensitized solar cells based on polyethylene oxide/multiwalled carbon nanotube/polyaniline gel electrolyte

Abstract

We have synthesized rare earth element cerium (Ce3+) doped TiO2 nanoparticles by using hydrothermal method. This doped TiO2 is used as photoanode in dye sensitized solar cells (DSSCs). The nanoparticles were characterized by using X-ray diffraction (XRD), energy dispersive X-ray (EDX) and UV–visible spectroscopy. From XRD it was found that the anatase crystalline phase keeps unchanged after Ce3+ doping while the crystallite size decreases. There is a decrease in the band gap of doped TiO2 is observed, Ce3+ positively changes the conduction band minimum of TiO2 due to the introduction of unoccupied 4f states of Ce3+. The gel electrolyte was prepared by in situ polymerization of aniline in the mixture of PEO and c-MWCNT. The synthesized gel electrolyte was characterized by Fourier transform infrared spectroscopy (FTIR), SEM, and EDX analyses. The thermal stability of these gels also increased with the addition of c-MWCNT. The present study is concerned with effect of c-MWCNT and Ce3+ on the conversion efficiency of the quasi solid state DSSCs. DSSCs fabricated with 0.1% c-MWCNT c in PEO/PAni and TiO2 as photoanode achieved maximum conversion efficiency of 1.62%. The introduction of c-MWCNT improved ionic conductivity of composite electrolytes and enhanced interfacial contact between electrode and electrolyte. The Ce3+@TiO2 photoanode influences the performance of DSSCs due to the increased electron injection. 0.5wt% Ce3+@TiO2 photoanode gives a maximum PCE of 4.08%, Jsc of 7.36mAcm−2 and Voc of 0.76V.