Graphene–TiO₂for scattering layer in photoanodes of dye-sensitized solar cell

Abstract

The scattering layer in the TiO2 photoanode (PAs) of dye-sensitized solar cells (DSSCs) is doped with single-layer graphene (G), and DSSC is prepared by doctor blade coating method. A small amount of graphene (0.0016 wt.%) in a graphene aqueous solution (G-AS) and a G-TiO2 paste was prepared to make 2–20 wt.% of G-AS in the deionized water (DIW). The UV-Vis measurement results show that the TiO2 scattering layers doped with graphene effectively improve the visible light absorption intensity of DSSC PAs and increase the current density (Jsc) from 13.84 mA/cm2 to 16.20 mA/cm2. The Electrochemical Impedance Spectroscopy (EIS) measurement showed that the internal structural impedance Rk [Formula: see text] decreased from 12.086 [Formula: see text] (without graphene doping) to 9.875 [Formula: see text] at 5 wt.% of the graphene doping. The photoelectric conversion efficiency (PCE) increased from 6.56% of the original un-doped graphene to the maximum PCE value of 7.57% at 5 wt.%. The results show that the best PCE is obtained when the concentration of G-AS is 5 wt.%.

A Novel Dye-Sensitized Solar Cell Structure Based on Metal Photoanode without FTO/ITO

“…A good photoanode should have a large specific surface area and a nanoporous structure, which can absorb dyes to the maximum and transmit photogenerated electrons quickly, and have sufficient porosity to penetrate the electrolyte [13][14][15]. Because TiO 2 is nontoxic, cheap, and has strong ability to adsorb dyes [16,17] and transfer electrons [18], it is widely used in the fabrication of photoanodes [19][20][21][22][23][24][25]. The introduction of special nanoparticles into a TiO 2 matrix can improve the performance of DSSCs, such as adding nanodiamonds (NDs) and CdTe nanoparticles [26,27], but the scarcity of materials will increase production costs.…”