Two kinds of graphene-based composites for photoanode applying in dye-sensitized solar cell

Two kinds of graphene modified TiO 2 composites are synthesized by hydrothermal method and layer-by-layer self-assembly technology. Graphene/titanate nanotubes (GTNTs) films have great light-harvesting efficiencies, and the amount of graphene does not obviously influence their optical performance. Alternating graphene/TiO 2 (prepared by supercritical treatment, GSCT) multilayer films possess superior electron transport ability, and the number of bi-layers plays as a central role for their electrical property. The outstanding light scattering and carrier transport properties of these promising films promote the performance of dye-sensitized solar cells (DSSCs). The power conversion efficiencies ( η ) of the DSSCs reach 6.46% and 7.54% under AM-1.5G by using GSCT-P25 (10 μm) and P25-GTNTs (15 μm) photoanodes, and the increases are 33.8% and 20.6% compared with that of by using a P25 photoanode with same thickness. The η reaches 8.67% when a preliminarily optimized GSCT-P25-GTNTs (15 μm) photoanode is adopted, which is far better than employing a pure P25 photoanode (6.25%).