用拉曼光谱手段对CVD方法生长的金刚石膜,特别是其中最有争议的1145cm^-1附近的拉曼峰进行了研究.用不同波长激光激发得到此峰的拉曼谱与量子尺寸选择效应所预期规律的相反,反驳了将1145cm-1附近的拉曼峰指认为纳米晶金刚石本征峰的说法.而通过对不同样品的比较,从侧面支持了将它归结为杂质,即反式聚乙炔的指认.更进一步通过分析不同尺寸的样品中杂质峰的相对强度,提出了这个蜂的强度或许可以作为金刚石晶粒尺寸判据的建议.

The Raman spectra of diamond films, prepared by CVD are studied, with special attention on the controversial Raman peak around 1145cm^-1. It was said that this is the fingerprint of nano-crystalline diamond. However, under various excitation laser lines, the behavior of the peak is opposite to that expected from the quantum size selection effect. Our results on different kinds of samples support the assignment that this peak is from residuals in the preparation, possibly trans-polyacetylene. Furthermore, by comparing the relative intensity of this Raman peak from every sample, we think the intensity can be used to judge the grain size within the diamond film. By this means, we can tell the quality of CVD diamond film conveniently.