Preparation And Performance Study Anode Of Dye-sensitized Solar Cells

The solar energy is abundant and infinite, and it is one of the best ways to solve the energy crisis. The solar cell is a set that transforms directly the energy of light into the electrical energy. Since long-term, the silicon-based solar cell is very difficult to substitute for conventional energy source truly to be widely used due to its high cost. As one kind of new solar cells, dye-sensitized solar cells (DSSC) have attracted more attention due to low-cost and simple technique recently. In our work, three methods (sol-gel, electrospinning and self-assembled) to prepare various nanostructure TiO₂ or ZnO photoanode were introduced. The performance of DSSC dependent on various nanostructure photoanode was studied in detail.TiO₂ and ZnO films were fabricated by sol-gel. The SEM pictures showed that all films were consisted of nanoparticles with the size about 20 nm, and the XRD date indicated that TiO₂ and ZnO films belonged to wurtzite and anatase phase, respectively. After absorbing the natural dye, the J-V measurements for the solar cells were performed. The overall light to electricity conversion efficiency (η) was very low which may be due to the character of films flat and limited porosity. Moreover, the low capacity to light harvest of the self-made natural dye could also decrease cell efficiency.Nanofiber TiO₂ films were prepared by electrospinning method and a poor adhesion of electrospun films to the substrate is found. In this regard, the ethanolamine (MEA) was added into the electrospun solution and the adhesion was greatly improved. After adding MEA into the electrospun solution, the preparation method used here is called as electric spray-coating due to the TiO₂ film consisted of nanoparticles. The morphology of films was investigated by field emission scanning electron microscopy (FESEM) and it appeared that the film is porosity and particles possessed the uniform size. The particle size and thickness of films could be easy controlled by changing the weight of MEA added and the volume of electrospun solution, respectively. The size of particle increased as more MEA was added. The performance of the cells dependent the weight of MEA added into the electrospun solution and the thickness of the TiO₂ films were studied, respectively. When the thickness of film is 2μm, the conversion efficiency increased to 2.91%. Due to the character of electric spray-coating technique, simple, versatile, and cost-effective, a very suited method to prepare nanoparticles TiO₂ film based DSSC was found, and it may be important in the industrial manufacture for the DSSC.ZnO sub-micrometer spheres were synthesized by self-assembled, and they were applied in DSSC. We found higher conversion efficiency was achieved compared with ZnO films prepared by sol-gel. ZnO sub-micrometer spheres have some advantages: 1) the light scattering was greatly enhanced which improved the light absorbing when ZnO spheres were used in DSSC. 2) The ZnO spheres have large surface area compared with ZnO films prepared by sol-gel.