掠射和θ-2θ方式X射线衍射分析In掺杂ZnO薄膜结构特性

In-doped ZnO thin films were successfully deposited on quartz substrates by sol-gel spin-coating technique. The structural properties of these films were investigated by x-ray diffraction at grazing incidence (GI-XRD) and conventional θ-2θ geometry (C-XRD). It is found that (002) and (103) diffraction peaks are predominant in the GI-XRD patterns (incidence angleα=1°), and when above the critical In doping concentration (～2 at.%), which is related to the solid solubility, the (103) peak gradually becomes the main growth orientation instead of the (002) peak. However, all the thin films only have a preferred (002) orientation in the C-XRD patterns, and the concerned (103) peak doesn’t appear. The doping concentration of 1 at.% is proved to be optimum for In-doped ZnO thin films. Based on the different penetration depths of x-rays between two scattering geometries, it is suggested that the ZnO thin films have different crystal structures at the surface and in the bulk.