沉积气压对电弧离子镀制备ZnO薄膜的结构和性能影响

采用阴极真空电弧离子镀技术在玻璃衬底上制备出了具有择优取向的透明ZnO薄膜. 利用X射线衍射仪、扫描电子显微镜及紫外-可见吸收光谱仪分别对ZnO薄膜的结构、表面形貌及可见光透过率进行了分析.XRD结果表明,所制备的ZnO薄膜具有六角纤锌矿结构的(002)和(101)两种取向,在沉积气压＞1.0Pa时所制备的ZnO薄膜具有(002)择优取向,并且非常稳定.SEM图表明,ZnO晶粒大小较为均匀,晶粒尺寸随着气压升高而变小.在400～1000nm范围内,ZnO薄膜的可见光透过率超过80%,吸收边在370nm附近,所对应的光学带隙约为3.33～3.40eV,并随着沉积气压上升而变大.     

脉冲偏压作用下MgO薄膜表面的荷电效应

采用脉冲偏压电弧离子沉积技术在玻璃基片上制备了透明的、具有择优取向的MgO薄膜。针对绝缘性薄膜表面的荷电效应,比较了脉冲偏压作用下鞘层对离子的加速时间(即鞘层的寿命)与脉冲宽度的大小以及偏压鞘层的初始厚度与离子穿越的距离的大小,讨论了不同占空比下偏压鞘层对离子的加速效应。利用X射线衍射及扫描电子显微镜对样品的观察结果表明,由于荷电效应,脉冲偏压幅值为-150 V,占空比在10%~40%的范围内,占空比的变化并不能改变MgO薄膜的微观结构和表面形貌。     

沉积气压对电弧离子镀制备MgO薄膜的结构及性能的影响

采用阴极真空电弧离子沉积技术在玻璃及Si衬底上成功地制备了具有择优结晶取向的透明MgO薄膜。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）及紫外-可见吸收光谱仪分别对MgO薄膜微观结构、表面形貌及可见光透过率进行了测试与分析。XRD结果表明,所制备的MgO薄膜具有NaCl型立方结构的（100）、（110）和（111）3种结晶取向,在沉积气压为0.7～3.0Pa的范围内,薄膜的择优结晶取向随沉积气压的升高先由（100）转变为（110）,最后变为（111）。SEM图表明随着沉积气压的升高,MgO薄膜的晶粒逐渐变小,薄膜结晶质量变差。在380～900nm范围内,沉积气压为0.7Pa下制备的MgO薄膜其可见光透过率高于90%,随着沉积气压的升高,薄膜的可见光透过率有所下降。     

Plasma-Neutral Gas Structure in a Magnesium Cathodic Arc Operating at Oxygen Gas with Experimental Comparison

The plasma-neutral gas structure generated in a magnesium cathodic arc operated with oxygen gas at a constant current of 50 A has been investigated by employing a simplified one-dimensional fluid model.The model includes elastic collisions and charge-exchange reactions between metallic particles and gas molecules,and also generation and recombination of gaseous ions by electron impact.The distribution profiles of density and velocity of species along the axial direction were obtained at diferent background gas pressures(in the range of 0.7~3.0 Pa)by this model.A comparison with the experiments was made.At lower gas pressures,the depositing particles were mainly the metallic ions with a larger kinetic energy.As the gas pressure increased,the magnesium atoms with smaller kinetic energy acted as the dominant depositing species.Determined by the minimization of the system’s total energy,MgO(100)or/and MgO(110)orientation appeared easily in the MgO films at lower gas pressures,and at higher gas pressures,the film preferred orientation was MgO(111).