Micro-structure And Optical Properties Of Low-dimensional Zinc Oxide Materials

Zinc oxide is a II-IV wide band-gap (3.37eV) compound semiconductor with wurtzite crystal structure. Due to the large exciton binding energy of 60meV, which ensures the high efficient excitonic emission at room temperature, it is regarded as one of the most promising materials for fabricating efficient ultraviolet (UV) and blue light emitting devices. Since the first observation of the stimulated ultraviolet emission at room temperature, ZnO has become another hotspot in the region of UV light emitting researching. For the abundance of the raw material, the low cost, the unharmfulness to the environment and the suitability for epitaxial growth, ZnO has a great potential for the widely application in the information and display industry.In this dissertation, high quality (002) textured ZnO films were prepared on silicon substrate using electron beam evaporation method. In addition, ZnO nano-particle material embedded into MgO thin films was prepared by a co-evaporation (thermal and electron beam evaporation, simultaneously) method and a following post-annealing process in oxygen ambient. X-ray diffraction (XRD), transmission and absorption spectroscopy and photoluminescence spectroscopy were employed to study the optical properties of ZnO films and nano-particles. The relationship between the optical properties and the crystallinity was discussed.The experimental results show that the quality of ZnO films prepared by electron beam evaporation can be greatly improved by means of annealing in oxygen ambient, and it is feasible to fabricate ZnO nanoparticle embedded in MgO thin films by the co-evaporation and post-annealing method. This method gives a new path to prepare low-dimensional ZnO quantum dots in MgO matrices.