The Research Of ZnO Doping And Its Thermal Properties

Zinc oxide(ZnO)has the advantages of high exciton binding energy,non-toxic,low cost,strong anti-radiation ability and excellent resistance to voltage breakdown,which are widely used in liquid crystal displays,sensors,satellite mobile communications and other devices.ZnO has good thermal conductivity,high carrier saturation drift speed,wide band gap,and is a good candidate for thermal research.In addition,as a semiconductor material,the internal impurities and defects will also determine its thermal properties.Therefore,the study of the thermal properties of ZnO films is of great significance to the thermal management and thermal design of related nanodevices.In this paper,the thin films of ZnO,aluminum-doped ZnO(AZO)and cobalt-aluminum co-doped ZnO(ZnO:(Al,Co))were grown using magnetron sputtering with the same growth parameters on the substrate of graphite film.The effects of different doping on the film structure,thermal conduction and thermal rectification of ZnO were studied by X-ray diffraction,scanning electron microscopy,laser flicker,MMR Seebeck coefficient measurement,etc.And the characterization and analysis results were used as the references for the design of heat flow design management.By means of experimental characterization,we found that AZO films have better C-axis preferential growth.Compared with the other two films,the thermal diffusion coefficient of vertical direction is larger,that is,direction of crystal growth will have an impact in the direction of heat conduction of difficulty.On the basis of the aluminum doping amount(2%wt)of AZO,doping with 10%wt of Co will be detrimental to the formation of ZnO crystals and increase the scattering of the atoms so that the thermal diffusion coefficient of ZnO:(Al,Co)in the direction of vertical and in-plane is reduced.AZO have a better crystal quality,and the absolute value of Seebeck is greater than the other two.In the Seebeck coefficient,AZO also has a higher Seebeck absolute value,but the ZnO:(Al,Co)has the minimum,All of them are negative,indicating that Zinc Oxide is N type semiconductor material.In the process of studying the thermal rectification effect of the material,it is found that the main factors that affect thermal rectification in the direction of the transverse are the different paths of the heat flow.Inspired by this experiment,designed by changing the heat flow path to get the effect of thermal rectifier components.