Study On The Magnetism And Optical Properties Of Doped ZnO Thin Films

In recent years, magnetic semiconductors (MSs), with coexisting ferromagnetic and spin transport properties at room temperature have attracted enormous interest due to their potential application in spintronic devices, this is because its properties both in ferromagnetic charge and electrons at room temperature. How to prepare dilute magnetic semiconductors at room temperature so that it can be applied to the preparation of the spin device become the people’s hot studied. ZnO as a wide band gap semiconductor has a larger excitation energy (60meV) and ZnO with high chemical and thermal stability and ZnO has a wealth of resources to get easy and other advantages, so the studies of ZnO also has considerable significance. Recently, studies of ZnO-based diluted magnetic semiconductors have become a hot spot, but so far the origin of the magnetic ZnO-based diluted magnetic semiconductors remains controversial.For example, the orgin of ZnO based diluted magnetic semiconductor, the influence of non-magnetic and magnetic element doped in magnetic property, the role of semiconductor defect in diluted magnetic property and so on. In this paper we prepared the non-magnetic and magnetic doped ZnO diluted magnetic semiconductor thin films. We main study the diluted properties of Mg and Co doped ZnO semiconductor thin films, and combination the PL spectrum study the magnetic properties of Mg, Co:ZnO films. The main contents are as follows:1. In this paper. Mg、Co doped ZnO thin films has prepared by pulsed laser deposition, the single-crystal Si (100) was select as film substrate. We study the structure, morphology, magnetic and optical properties of the film under different elements, content and annealing temperature and other different conditions. Experiments show the doped films with a hexagonal wurtzite structure and cubic structures based on different doping content and the magnetic property change with different structure. It reveals the strong correlation between ZnO semiconductor structures and magnetic property. It provides a valuable experimental for the development of ZnO diluted magnetic semiconductor material.2、We studied non-magnetic Mg-doped ZnO thin films. The results show that, all Mg-doped ZnO films at room temperature showed a good ferromagnetism. Change Mg content in ZnMgO film found, when the Mg content is lowly, the film has a single ZnO (002) peak, indicating that the sample exhibits hexagonal ZnO structure. When the Mg content continues to increase film appeared MgO (200) peak, indicating that the film appeared in cubic MgO phase. Change the atmosphere of oxygen pressure ZnMgO,film and found that the annealing temperature, the oxygen pressure increases on the magnetic thin film has a certain effect of increasing the annealing temperature is decreased to increase the magnetic thin film.3、ZnO thin films doped with magnetic particles Co has been studied in this paper. The results show that, Co can doped into the ZnO lattice, but because it is difficult to doped into the crystal lattices, so the Zn、Co mixture was generated. With the content of Co changed the crystalline phase did not change significantly, with Co content increases the magnetic of the film decreases but go on increases the Co content the magnetic increases. Change the annealing temperature of the ZnCoO film found, the magnetic weakened with the annealing temperature increases and luminous intensity decreased as the annealing temperature increases too.