Chang Geng-Rong, Ma Fei, Ma Dayan, Xu Kewei
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
J Nanosci Nanotechnol. 2011 Dec;11(12):10824-8. doi: 10.1166/jnn.2011.4025.
Amorphous Si-rich silicon carbide films were prepared by magnetron co-sputtering and subsequently annealed at 900-1100 degrees C. After annealing at 1100 degrees C, this configuration of silicon quantum dots embedded in amorphous silicon carbide formed. X-ray photoelectron spectroscopy was used to study the chemical modulation of the films. The formation and orientation of silicon quantum dots were characterized by glancing angle X-ray diffraction, which shows that the ratio of silicon and carbon significantly influences the species of quantum dots. High-resolution transmission electron microscopy investigations directly demonstrated that the formation of silicon quantum dots is heavily dependent on the annealing temperatures and the ratio of silicon and carbide. Only the temperature of about 1100 degrees C is enough for the formation of high-density and small-size silicon quantum dots due to phase separation and thermal crystallization. Deconvolution of the first order Raman spectra shows the existence of a lower frequency peak in the range 500-505 cm(-1) corresponding to silicon quantum dots with different atom ratio of silicon and carbon.
通过磁控共溅射制备富含非晶硅的碳化硅薄膜，并随后在900-1100摄氏度下退火。在1100摄氏度退火后，形成了这种嵌入非晶碳化硅中的硅量子点结构。利用X射线光电子能谱研究薄膜的化学调制。通过掠角X射线衍射表征硅量子点的形成和取向，结果表明硅和碳的比例显著影响量子点的种类。高分辨率透射电子显微镜研究直接表明，硅量子点的形成强烈依赖于退火温度以及硅与碳化物的比例。由于相分离和热结晶，只有约1100摄氏度的温度足以形成高密度和小尺寸的硅量子点。一阶拉曼光谱的去卷积显示在500-505厘米-1范围内存在一个较低频率的峰，对应于具有不同硅和碳原子比的硅量子点。
