Composite Thin Film And Optimization Of Dye-sensitized Solar Cell

Dye sensitized solar cell is the third generation of solar cell, which is rich in raw materials, low cost, green environmental protection, simple technology and so on. So it has become a hot research topic. This paper summarized the principle, structure, research progress of the dye sensitized solar cell and the method of preparing semiconductor oxide and modifying the semiconductor oxide;the pure ZnO film light positive electrode is made by sol-gel spin coating method.At the same time,the semiconductor SnO₂ is introuduced into pure ZnO thin film by chemical bath dipping method to prepare ZnO/SnO₂ composite thin film light positive electrode. The crystal form of the film,the surface topography and optical properties are characterized in modern methods such as XRD、SEM and ultraviolet- visible- near infrared spectrum. Afterwards the photoelectric property of the assembled cell is been tested.Zinc oxide with a wide and direct band-gap is a candidate for solar application due to its advantages,such as thermal stability,easy to prepare.The process parameters of ZnO film made by sol-gel spin coating method are optimized through orthogonal test,in which three main influencing factors（heat treated temperature, coating layer and heat treatment time） are studied. The results show: heat treatment temperature affects the photoelectric properties of thin films most, and the time of heat treatment is the smallest;The optimum technological scheme is: heat treatment for 60 minutes under 500℃,6 layers of coating.In this paper, the wide band gap semiconductor oxide SnO₂ is introuduced into pure ZnO thin film by chemical bath dipping method to prepare ZnO/SnO₂ composite thin film light positive electrode. The optical properties and surface topographies of the ZnO/SnO₂ are characterized by ultraviolet-visible-near infrared spectrophotometer and field-emission scanning electron microscopy. The affects of soaking time onto the optical and electrical. the results was drawed as follows: SEM photo shows SnO₂ wrap the ZnO particles which will increase the specific surface area and the dye adsorption. J-V test indicates that the ZnO film soaked into 0.3 M SnO₂ solution for 40 minutes has the best improvement of the structure and electrical properties,which has increased compared with pure ZnO thin film.