High Efficient Transparent TiO2 Nanotube Dye-Sensitized Solar Cells: Adhesion of TiO2 Nanotube Membrane to FTO by Two Different Methods

In order to fabricate transparent TiO2 nanotube dye-sensitized solar cells, anodically growth nanotube membranes are detached from Ti substrate by a re-anodization method. The membranes are transferred on FTO glass by two different methods. At the first one, 100mM Ti-isopropoxide is used to make TiO2 nanoparticles for adhering TiO2 nanotube membranes to FTO and in the second one a commercial TiO2 nanoparticle paste is used as connector material. In order to investigate the effect of annealing temperature on the crystallinity of the photoanodes, they were annealed in temperatures from 350 to 650°C. All of the annealed photoanodes show high crystallinty and pure anatase phase in both cases. However nanoprticles with large diameter about 500nm and no homogeneity of dispersion of them at the first method leads to week interconnection between membranes and FTO glasses but good interconnection at the second method leads to high power conversion efficiency of 6.13% under 1 sun illumination without any extra treatment.