不同激发波长下典型化学气相沉积法合成钻石拉曼光谱异同特征

Similarities and Differences of Raman Spectra of Typical Chemical Vapor Deposition-Grown Synthetic Diamonds Under Different Excitation Wavelengths

在在室温下分别以405、532、785 nm为激发波长对典型化学气相沉积法(CVD)合成钻石的拉曼(Raman)光谱特征进行了对比研究。结果表明:1)同一激发波长下,钻石及其中的光学缺陷对应的Raman特征峰随着激光能量的增大更趋明显,且对应的特征峰位不随激光能量的增大而频移。同为Ⅱ型钻石,因不同颗钻石中的杂质元素的赋存不同或钻石后期的处理方式的差异导致同一激发波长下其对应的Raman谱图存在一定的差异;2)不同激发波长下,同一颗钻石的Raman光谱中在1332 cm-1处均存在特征峰。同时,归属钻石的Raman本征峰并不随激发波长的改变而发生频移。相反,钻石中的杂质或经钻石自身后期处理等因素引起的光学缺陷的呈现形态与激发波长的选用密切关联。该研究工作对应用Raman光谱对钻石晶体结构信息进行表征及区分钻石的本征峰与其中的光学缺陷特征峰具有重要的指导意义。

Raman spectra of the typical chemical vapor deposition(CVD)synthetic diamonds were compared when excited with 405,532,and 785 nm wavelengths,respectively,at room temperature.The results show that:1)at the same excitation wavelength,the Raman peaks corresponding to the intrinsic structure or optical defects become more obvious with the increase of laser power,and the corresponding peak positions do not shift with the increase of laser energy.Moreover,there are some spectral differences even though these diamonds all belong to the type II,including the occurrence characteristics of impurity elements and the methods of treatment,which result to some differences for the Raman spectra during these diamonds are excited by the same wavelength;2)the characteristic of sharp peak locates about1332 cm-1all existed in the Raman spectra of each of diamonds when excited under different wavelengths.Meanwhile,the intrinsic peaks of diamond do not shift with the change of excitation wavelength.On the contrary,the appearance of the optical defects caused by impurities or post-treatment is closely related to the selection of excitation wavelength.This work provides important guidance for the characterization of the structural information of diamond by Raman spectroscopy and the identification of intrinsic peak and optical defect characteristic peak of diamond.