Preparation And Performance Of ZnO-based Composite Films By Magnetron Sputtering

ZnO-based thin films are considered as a new transparent conducting material due to its excellent optical and electrical properties.On the basis of experimental research on ZnO materials,ZnO thin films have been applied to solar cell,liquid crystal displays,thin film transistors and other fileds.In this work,not only Mg-Al-Ga:ZnO（MAGZ）but also MAGZ/Cu/MAGZ multilayer films are deposited on glass substrate by magnetron sputtering.The structural,morphological,optical and electrical of all samples are measured by X-ray diffraction（XRD）,atomic force microscope（AFM）,field emission electron microscope（SEM）,ultraviolet visible spectrophotometer and hall effect measurement,respectively.The main contents and conclusions of this work are as follows:（1）MAGZ films with different thickness are prepared on glass substrate by magnetron sputtering.The results of XRD display that only（002）diffraction peak can be observed.Moreover,the intensity and diffraction angle of（002）peak increase slightly with the increase of thickness,which can be attributed to the reduction of interplanar spacing and residual stress in films.The average grain size of samples is about 30 nm and the grains are distributed evenly.The average transmittance of all samples are above 85%.When the thickness is about 250 nm,the optimal values of resistivity,carrier concentration and mobility of MAGZ films are 8.37×10^-3Ω·cm、1.12×10^-20cm^-3and 6.41 cm²V^-1s^-1,respectively.The dependence of temperature and electrical of 250-nm-thick sample indicates that MAGZ film exhibits typical semiconductor behavior.（2）MAGZ/Cu/MAGZ multilayer films are deposited on glass substrate by magnetron sputtering.Through the analysis of XRD results,it can be found that the peak intensity of（111）diffraction peak of Cu layer becomes stronger as the increase of thickness,and the intensity of diffraction peak corresponding to ZnO decreases.Which means that Cu layer inhibits the growth of MAGZ films.The electrical performance text results show that resistivity of MAGZ/Cu/MAGZ multilayer films have been reduced significantly.When Cu thickness increases from 3 nm to 11 nm,Cu layer forms continuous film gradually and reistivity of multilayer film decreases to 1.24×10^-4Ω·cm rapidly.When Cu thickness is further increased to 25 nm,resistivity of samples reduces to 7.31×10^-5Ω·cm slowly.Furthermore,with the increase of Cu thickness,the average transmittance of samples decreases from 86%to 35%.This phenomenon can be explained by the absorption and reflection of Cu layer.