【摘要】 用直流反应溅射在硅基片上生长具有高取向晶粒的氧化锌薄膜,在氧气、氮气、空气气氛和不同温度下进行热处理,对所得到的样品用俄歇谱(AES)仪进行元素深层分布分析,并测量光致发光光谱。研究结果表明: 1.经热处理的薄膜表面全部为缺氧表面,不同深度Zn和O含量分布(Zn/O)有所不同; 2.当在氧气氛中1 000℃下热处理后,在薄膜的深层可产生比较明显的氧过量;而在空气中950℃下热处理后,则可产生局部氧过量; 3.光致发光谱表明,薄膜中全部为锌过量时产生纯紫外发射,而具有局部氧过量的薄膜则在产生紫外发射的同时产生绿色发光,绿光和紫外的强度比则随局部氧过量增多而增大。更多还原

【Abstract】 There are many viewpoints about green emission center in ZnO films, such as V O (donor) or O Zn (acceptor). In order to control the emission spectra, it’s important to find out green centers of ZnO films. ZnO films were grown on Si substrates by DC reaction sputtering. After growing the samples were heat treated in different temperatures and oxygen partial pressures. X-ray diffraction patterns indicate all films have 0002〉 preferred orientation, but the film treated in 1 000 ℃ in N 2 ambience has a lattice constant larger than that of other samples and its lattice was larger distortion in lattice. We guess that a lot of interstitial zinc (Zn i) was generated in the film, as a result of annealing in the ambience of lack of oxygen. Depth analysis of element contents by Auger electron spectroscopy (AES) indicates the distributions of Zn and O in ZnO films were different due to different annealing conditions. Photoluminescence spectra of all films show two emission peaks at 3.18 eV (ultraviolet) and 2.38 eV (green), except the Sample 1 #(annealed in N 2), which has a 3.18 eV peak only . Comparing photoluminescence spectra of the films to the distributions of Zn and O by AES in the films, it was found that if O content exceeds that of Zn in any depth of film, the films generate green emission,and the green emission is stronger the more excess of O content. If O content exceeds Zn, the acceptors defects exceed donors in the monophase films. Therefore we suggest that green luminescence center is concerned in acceptor defects in ZnO grown on Si substrates by DC sputtering, the energy of green luminescence, 2.38 eV , is centered O Zn , comparing with energy band calculation.更多还原