将Zn/F离子先后注入到非晶二氧化硅中并分别在400,600,700℃下进行了退火.用光学吸收谱、透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)对退火的样品进行分析,发现在600℃退火后ZnO量子点已经形成.二次离子质谱仪(SIMS)测试发现在溅射时间为2S时Si,Zn元素同时出现,说明没有在衬底的表面形成ZnO薄膜.从原子力显微镜(AFM)图像看到有少量的颗粒被蒸发到衬底的表面,说明在衬底的内部形成了ZnO量子点.F离子注入的作用为在衬底的内部形成ZnO量子点提供了O2分子.
Zn and F ions were implanted into silicon sequentially, and then the implanted specimens were annealed at 400, 600 and 700 ℃. Optical absorption spectra, transmission electron microscope (TEM) and high-resolution transmission electron microscope (HRTEM) were used to analyze the as-implanted and annealed specimens. It was found that ZnO quantum dots had been formed after annealing at 600 ℃. Secondary ion mass spectrometry (SIMS) results show that Si, Zn elements appeared at the same time after sputtering for 2 s, so ZnO film did not formed on the surface of the substrate. Atomic force microscopy (AFM) images show a comparatively flat surface of the annealed samples which indicates only very few Zn atoms are evaporated to the surfaces. The formation of ZnO quantum dots during the thermal annealing can be attributed to the direct oxidization of Zn nanoparticles by the oxygen molecules in substrate produced during the implantation of F ions.