This study has demonstrated that GNF films with good electrical properties have been successfully fabricated on FTO substrates using a doctor blade method and thermally annealed at various conditions. The GNF/FTO film was found able to enhance DSSC devices in argon ambient rather than in air and at annealing temperature higher than 380 °C. The PCE enhancement was mainly due to the lowered oxygen concentration in the film and the elevated electrical conductance. The DSSCs fabricated with a GNF counter electrode could reach a PCE of 6.08%, around 88% of that with a Pt counter electrode, suggesting that GNF is a highly potential candidate to replace Pt catalyst.