Preparation of nanocrystalline TiO2 electrode by layer-by-layer screen printing and its application in dye-sensitized solar cell

The TiO2 colloidal solution was prepared by the sol–gel method, in which the diameters of most TiO2 nanoparticles were about 9.7 nm. Further, multilayered TiO2 films were obtained by layer-by-layer screen printing. The adsorption processes of multilayer films in UV region are linear and reproducible for sequential deposition cycles by screen printing. The morphology of TiO2 electrode was characterized using scanning electron microscopy and the sizes of particles on the TiO2 electrode surface were about 60 nm. The morphology of representative field on the TiO2 electrode surface was magnified different times, the observed results indicated the surface of film electrode is composed of uniformly interconnected particles and pores, so the screen printing can be applied in the preparation of TiO2 films with large dimension. The TiO2 electrode was used as working electrode for copper aminophthalocyanine sensitized solar cell, the maximum incident photon-to-electron conversion efficiency of 13% was achieved at wavelength of 450 nm and 697 nm.