Zno Preparation, Characterization And Properties Of Nanometer Semiconductor Materials Research

Zinc oxide(ZnO) is a kind of direct band gap of wide band gap semiconductor materials, which can be fabricated by simple methods. And during the material growth process, it shows good orientation, which is favorable for preparing various materials with different types of morphology, such as nanowires and nanobelts. Owing to its good photoelectric properties, it can be used as the photoanode of the dye-sensitized solar cells. Besides, ZnO nanomaterials own small microscopic size and large specific surface area, so its surface shows a distinctive wettability, which has also become a hot research focus.The main content of this thesis owns two parts. For the first part, ZnO materials are studied as photoanode materials of dye-sensitized solar cells. ZnO films on the substrates were synthesized successfully by using both sol-gel and powder spin besmear methods. Then, dye-sensitized solar cells were assembled by using these two types of films as photoanodes, respectively, sensitized by carminum pigment. The solar cells assembled by the first type of film performed better than those by the ZnO films fabricated by powder spin besmear method. Comprehensively considering the advantages of these two methods, ZnO films were prepared by using the method of sol-gel to doped zinc oxide powder and they were used as the photoanodes of the solar cell, whose performance has been greatly improved. In addition, the zinc oxide nanowire arrays film were synthesized successfully using hydrothermal synthesis method, but the solar cell performance is not satisfactory. For the second part, the surface wettability of the zinc oxide materials with different morphologies were researched. We first prepared ZnO thin films by the sol-gel, and the forward contact angle of the ZnO thin film surface is about70°. And surface contact angle is about103°for ZnO nanowire arrays synthesized by the hydrothermal method. Comparing the wettability of these two types of materials, it can be found that interstitial air between the nanowires of ZnO array enhances the hydrophobicity, which makes the zinc oxide surface become more hydrophobic. Finally, we used the AFM (the Dimension the Icon SPM, Bruker, original DI Company) in the electrostatic scanning mode (EFM) to characterize the surface morphology and surface charge distribution of ZnO nanowire arrays. By observing the AFM measured surface topography, it can be found that the surface of ZnO nanowire arrays has small protrusions and the pillars of the zinc oxide nanowire arrays are negatively charged.