Stability improvement of the ZnO nanowire array electrode modified with Al_2O_3 and SiO_2 for dye-sensitized solar cells

摘要

The surface destruction of the ZnO nanowire arrays that occurred in the sensitization process causes extreme decreases of the conversion efficiencies. In order to solve this problem, Al_2O_3 and SiO_2 layers are coated onto the surface of the ZnO nanowire arrays by spin-coating method, used as protection layers around the ZnO nanowire arrays. The roles of both types of layers have been investigated and discussed. The experimental results indicate that the surface modification with Al_2O_3 and SiO_2 nanoparticle layers can suppress the surface destruction, enhance the acid stability of ZnO nanowire array electrode, and slow down the decreasing rate of the conversion efficiencies.