Preparation, Doping And Optical Properties Of Low-dimension Semiconductor ZnO Nanomaterials

Nanoscale science and technology is a kind of new science and technology which has been born since 1980s and is growing up. Its basic meaning is to know and remake nature in the range of nanoscale, meanwhile operating and arranging atoms and molecules directly in order to create new materials. It mean research contents include, creating good- performance nano materials, producing kinds of nano apparatus and devices, probing and analyzing characteristic and phenomenon of nanometer district.Zinc oxide (ZnO) is one of the most promising materials for the fabrication of optoelectronic devices operating in the blue and ultraviolet (UV) region, owing to a direct wide band gap (3.37 eV) and a large exciton binding energy (60 meV ). Moreover, due to its superior conducting properties based on oxygen vacancies, ZnO has been investigated as transparent conducting and piezoelectric materials for fabricating solar cells, electrodes, and sensors.In this paper, preparation, growing mechanism and optical properties of low-dimension semiconductor ZnO nanomaterials are researched. Kinds of ZnO nanostructures of different appearance and sizes are prepared by simple method of thermal evaporation, such as ZnO nanowire, nanorod, branch-shaped nanomaterials, flower-like nanostructures and so on. Temperature, distance between raw materials and crystallizing field, carrier gas eg. of evaporating process influence the appearance, structure and properties of the products. Appearance, sizes and micromechanism of products are represented by SEM and TEM; structures and components are analyzed by XRD; their optical properties are measured and tested by PL and Raman spectrum..Structures, micro-appearance and optical properties of Bi-doped ZnO nanomaterials are researched and represented. It indicates that appearance and optical properties of Bi-doped ZnO products are different from pure ZnO products. After being doped, E₂ high peak of ZnO Raman spectrum shifts towards right, high frequency direction.In PL spectrum of Bi-doped ZnO, the position of UV shining peak appears"red shift"; peak width at half-height of UV peak increases and peak of green visible light disappears.