Investigation On The Photoluminescence Property Of Transition Metal Oxide Nanowire Arrays

In recent years, one-dimensional nanomaterials have been attracted much attention due to their superior electrical, optical, magnetic, mechanical and thermal properties, as well as their potential application in nanodevices, sensors, and lasers, and they are expected to show many interesting properties originating from the low dimensionality and the quantum fluctuations. The losses of many kinds of effect such as optical absorption, reflectivity and transition are closely related to the size effect of the nanomaterials. For example, optical fiber represents an important role in the area of communication and optical transmission. When the optical fibers take advantage of nanomaterials, the losses will be significantly lowed down and the efficiency of the light transmission will be improved greatly. Because of their distinguish properties such as semi-conductivity and magnetic property, transition metal oxide nanomaterials attract much attention among the nanoscience and nanotechnology area. Some main contents and innovations in this paper are listed as below:1. Large-scale ZnO nanowire arrays are synthesized by electrodeposition with subsequent heat-treatment in atmosphere ambient at 450-650°C. Field Emission Scanning Electronic Microscope and Transmission Electron Microscope results show that the length of ZnO nanowires is nearly 5μm and their diameter is about 70 nm. X-ray diffraction and electron diffraction results reveal that the ZnO nanowire is a polycrystalline structure. Photoluminescence is investigated at 295 K. Abnormal PL properties that an unusual sharp emission at 485 nm and a broad ultraviolet emission which are different from the other Photoluminescence work of ZnO before are observed. The possible explanation of all the distinct results was discussed. And we feel that the sharpness of the blue emission may be valuable for the future applications of ZnO nano-laser devices.2. Co₃O₄ nanowire arrays were fabricated by electrodeposition with following heat-treatment in atmosphere ambient. Photoluminescence was investigated at 295 K. In the experiment, when increasing the excitation light wavelength from 260 to 360 nm, two kinds of emissions corresponding to the increasing excitation light wavelength were observed. One of them alters the excited emission position, another keeps its emission position. The distinct behavior of excited emissions related to the increasing excitation wavelength indicates that the mechanism of them must be different. According to the experimental comparison and first-principle calculation, the two kinds of emissions were discussed.