Luminescence Properties And Syethesis Of Li, Na And Mg Co-doped ZnO Thin-films

ZnO is an important function materials and a kind ofⅡ-Ⅵcompound wide direct band gap semiconductor material with hexagonal crystalline structure.Its band gap is 3.37eV at room temperature.Coupled with good electrical and mechanical performance with the high exciton binding energy(60meV).Currently,ZnO thin film have been more widely used on the surface acoustic wave devices,solar cells,gas-sensing and pressure-sensitive devices.And also has great potential for development on many other fields,such as UV detectors,LED,LD and so on.Many of the production technology of ZnO thin films are compatible with silicon and other semiconductor devices to achieve integration.So,the ZnO thin films have attracted more and more people's attention,and have broad application prospects.For the ZnO semiconductor materials,the intrinsic defects of crystal structure and doping can significantly affect its electronic and energy band structure,so its electrical conductivity properties,luminescent properties,chemical and magnetic properties have been changed greatly.Recently,there has been reported that Mg²⁺,etc.can be doped into ZnO to increase the band gap effectively,and the study ofⅠgroup elements doping also made some progress.In this paper,we prepared Mg andⅠ-group elements Li,Na co-doping ZnO thin films with the Sol-gel method which can be used in UV detector,SAW device,solar cells,optoelectronic devices and integrated application.We studied of the influece of different alkali metal-doped and the preparation of process parameters on the structure and optical properties of ZnO thin films,such as the impact of the coating process and different heat treatment.We intentded to find the best conditions to optimize the practical application of ZnO thin film properties.In our experiment,we prepared(Li,Mg):ZnO thin films with good c-axis preferred orientation,smooth surface and uniform particles,which are applicable to surface acoustic wave components.When Li were heavily doped,the thin film fit to produce Blu-ray luminescent material;The(Na,Mg):ZnO thin films also have good c-axis preferred orientation,and when doped lightly,the thin film has good ultraviolet luminescent characteristics to produce a kind of purple luminescent materials and UV detector.And through analysised the luminescence properties of two thin-films and found out that Li is accpter in the film and in the case of heavily doped,it entered the space of Zn;Na does not have an impact on the film luminescence when it was lightly doped,but when the doping concentration increases,they enter the space of Zn, resulting in a large number of oxygen vacancies,so that green light emitting peak appeared.