Preparation And Physical Properties Of Ni_xMg_1-xO Thin Films

UV photodetectors have important applications in many fields such as detection of missile tail flames,forest fire detection and space data transmission,making the development of UV photodetectors increasingly important.Ni_xMg_1-xO ternary oxide materials can be adjusted to control the optical band gap between 3.6e V and 7.8e V by component tuning,and are highly promising candidates for the preparation of UV photodetectors films,especially solar blind UV photodetector films.In this thesis,corresponding research work has been carried out on the properties of Ni_xMg_1-xO thin films and their preparation techniques,which consist of the following:Based on first principles,simulations of Ni_xMg_1-xO material properties were carried out using Materials Studio software.The Ni O crystal structure model was alternatively doped with Mg elements to establish the Ni_xMg_1-xO model with different Ni/Mg element ratios.The Castep module and Reflex module were used to simulate the material’s band structure,density of states,optical bandgap,and crystal structure.The results showed that Ni_xMg_1-xO is a direct bandgap semiconductor material and that Mg doping can effectively increase the bandgap width of the material.In this paper,Ni_xMg_1-xO thin films were prepared using radio frequency magnetron sputtering equipment and a dual-target co-sputtering method under different process conditions（sputtering time,sputtering pressure,target sputtering power,oxygen argon ratio）.The properties of the films such as orientation,crystallinity,transmittance,optical band gap,film components and content were investigated by X-ray diffraction（XRD）,UV-Vis spectroscopy and X-ray photoelectron spectroscopy（XPS）,and the influence of different process parameters on the properties of the film materials was given.The theoretical and technical basis for the in-depth study and preparation of Ni_xMg_1-xO thin film materials and devices is provided.