热氧化法制备ZnO薄膜及其特性研究

用热氧化金属Zn膜的方法在Si(111)衬底上制备ZnO薄膜。X射线衍射结果表明,500℃氧化的样品的结晶性能最好。随氧化温度的升高,薄膜内的应力方向在450~500℃之间发生转变,从沿c轴的张应力变为压应力。500℃氧化的样品的室温光致发光(PL)谱中,紫外峰的半高宽为94.8meV,其强度与深能级发射强度之比高达162。氧化温度超过700℃后,样品的PL谱以深能级发射为主,对此现象产生的原因进行了讨论。

ZnO Thin Films Prepared by Thermal Oxidation Method and It's Properties Study

ZnO thin films have been fabricated by thermal oxidation of metallic Zn films at different temperatures in air. The results of X-ray diffraction (XRD) show that the film prepared at 500℃ has the best crystallinity among all the films. As oxidation temperature increases, stress along c-axis in the samples changes from the tensile to the compressive, and the conversion temperature is in the range of 450~500℃. The full width at half maximum (FWHM) of ultraviolet (UV) peak for the ZnO film prepared at 500℃ is 94.8 meV, and corresponding photoluminescence (PL) intensity ratio of UV emission to deep-level (DL) emission is as high as 162 at room temperature. The DL emission becomes dominant in the PL spectra when oxidation temperature exceeds 700℃, and the possible origin of this phenomenon is also discussed.