The Preparation Of Photoanode Electrodes And Their Applications In Dye-sensitized Solar Cell

The first silicon solar cell fabricated in American Bell Lab in 1954 opens a new era of the application of solar energy. Because of the high conversion efficiency and mature producing techniques, silicon solar cell were mostly used in the world. But the high cost of the silicon made the silicon solar cell expensive and hard to used widely. The dye-sensitized solar cell (DSSCs) has received considerable attention because of its simple preparation process, low cost and stable performance.Zinc oxide with a wide and direct band-gap is a candidate for solar application due to its advantages, such as its excellent chemical and thermal stability, non-toxicity, and its transparency in the visible wavelength. The preparation of ZnO nanorod array films by a two-step method are studied in the second chapter. A layer compact and uniform ZnO nanoparticles with grain size of about 10 nm are obtained on the transparent conducting optically glass (TCO glass) via dip-coating method. The ZnO nanorod arrays are grown on the ZnO nanoparticle-coated TCO glass by using the hydrothermal method. We discuss the effects of experimental conditions such as substrate, the basicity and the pH value of precursory solutions on the formation and the morphology of the ZnO nanorod arrays. In the third chapter, ZnO nanorod powders are synthesized by using hydrothermal method, and porous ZnO nanorod film is obtained on TCO glass by using doctor-blade technique.The performance of the DSSCs based on porous ZnO nanorod film and ZnO nanorod array film are compared. The results show that the photocurrent and the fill factor of the ZnO array film is higher, although its thickness is thinner.Nanoporous TiO₂ electrode has high surface area, and can adsorb more dye molecular and electrolyte. So the photoinjected electrons are prone to recombination with the oxidized ions in the redox mediator or oxidized dye at the semiconducor surface. In order to inhibit the recombination of electron and cavity, coating another semiconductor around the TiO₂ particle as a barrier layer is an effective way. In the fourth chapter, preparation of TiO₂@MgO core-shell film is carried out according to a simple and low-cost chemical bath deposition method. TiO₂@MgO core-shell configuration is formed, in which the single crystal TiO₂ is the core and the amorphous MgO layer is the shell. The thickness of the MgO layer could be controlled by the dipping time. The performance of the DSSCs based on TiO₂@MgO electrode is investigated. Comparing with that of the pure TiO₂ electrode, the photocurrent, fill factor and energy conversion of the TiO₂@MgO electrode is improved.