铜掺杂纳米氧化锌薄膜的制备及光学特性

Preparation of Cu doped ZnO nanoparticle film and its optical properties

氧化锌(ZnO)是一种新型稀磁半导体材料,有优良的磁学及光学性质,透明度高,常温发光性能优异。根据半导体掺杂原理,以氧化锌为原料,过渡金属元素铜为掺杂元素,采用化学气相沉积法(CVD),制备了铜掺杂纳米氧化锌薄膜。利用晶向显微镜观察ZnO∶Cu在衬底硅片上的表面形貌和生长情况,利用光致发光谱和分光光度计分析了样品的光发射和光吸收特性,研究了薄膜的伏安特性。发现铜掺杂对氧化锌薄膜的光吸收和光发射以及表面伏安特性都有很大的影响。随铜掺杂含量的增加,光吸收强度明显增大,光发射峰更加丰富。适当掺杂量的情况下,电流明显增大,但掺杂量太大,会引入缺陷和晶界,反而会使漏电流增大。10%-20%掺杂量为比较理想的掺杂量。

ZnO,a new diluted magnetic semiconductor material, has excellent magnetic properties and optical properties, high transparency and luminescent properties at room temperature. In this paper we prepared nanome- ter ZnO：Cu film using ZnO as material doped with transition metal copper element by chemical vapor deposition （CVD）. The surface morphology and growth state of the obtained ZnO：Cu films were observed by metal phase microscope; the absorption and optical emission properties were analyzed by UV-Vis spectroscopy and luminescence spectrum; and the electrical properties were studied as well. The results show that the concentration of Cu impurity has large influence on the absorption, optical emission, and voltage-current properties of ZnO film. With the doping concentration of Cu increasing, the intensity of optical absorption was enhanced, luminescence bands getting rich, and the current was enlarged under the threshold concentration. Over the threshold, it produced large traps, dislocation, and crystal boundaries, leading to great leakage current. The acceptable concentration of Cu in ZnO film is 10%-20%.