Study on the Configuration and Applications of High Spectral Resolution Raman Spectrometer
LIU Zhao-jun1, ZHAO Cun-hua1, HAN Li-gang1, MO Yu-jun2*
1. College of Physics and Electronic Information, Luoyang Normal College, Luoyang 471022, China 2. College of Physics and Electronics, Henan University, Kaifeng 475004, China
Abstract:In the present paper the authors studied theoretically and experimentally the relationship between spectral resolution and grating density, the limitations to improve the spectral resolution by using high density grating, the use of longer focal length grating to increase spectral resolution without compromising instrument throughput and the effect of slit width on spectral resolution and sensitivity. Finally, two experiment results were provided to show why higher spectral resolution is important to ensure that critical information is not lost during a Raman measurement. Stressed silicon was produced by growing a thin crystalline layer of Si on an SixGe1-x substrate. It is possible to use Raman spectroscopy to probe the stress in the SixGe1-x and Si layers at the same time. The parameter to monitor the stress is the position of the Si-Si vibrational mode in SixGe1-x and Si. Such a measurement requires high spectral resolution because the peaks exhibit very subtle shifts. The authors’ results clearly demonstrate that the resolution offered by a high density grating is necessary to properly monitor the very small frequency shift of this cap-layer Si-Si mode in order to properly characterize the strain structure. The Raman band around 180 cm-1 is assigned to the radial breath mode of single wall carbon nanotube (SWCN). By measuring the frequencies excited with different laser, the diameters of the sample can be obtained. Practically, sample is always composed of SWCN with different but very close diameters and their Raman bands might overlap together and are difficult to determine the frequencies. The authors’ results showed that only higher resolution with the long focal length spectrometer can give accurate number and frequencies of Raman bands, which leads to a correct analysis of the diameter distribution.
刘照军1,赵存华1,韩礼刚1,莫育俊2* . 现代高分辨拉曼光谱仪的配置及应用研究[J]. 光谱学与光谱分析, 2010, 30(02): 567-570.
LIU Zhao-jun1, ZHAO Cun-hua1, HAN Li-gang1, MO Yu-jun2* . Study on the Configuration and Applications of High Spectral Resolution Raman Spectrometer . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2010, 30(02): 567-570.
[1] Long D A. Raman Spectroscopy. New York: McGraw-Hill, 1977. [2] McCreery R L. Modern Techniques in Raman Spectroscopy. Edited by Laserna J J, New York: JOHN WILEY & SONS, 1996. [3] LI Nian-zeng, YAN Da-yuan(李念曾,闫达远). Radiometry and Photometry(辐射度学和光度学). Beijing: Beijing Institute of Technology Press(北京:北京理工大学出版社),1990. [4] Goodman G, Pajcini V, Smith S. Materials Science in Semiconductor Processing,2005, 8: 255. [5] Tsang J C, Mooney P M, et al. J. Appl. Phys., 1994, 75 (12): 8098. [6] CHEN H, LI Y, PENG C, et al. Phys. Rev. B, 2002, 65(23): 233303. [7] TAN Yan, TANG Yuan-hong, PEI Li-zhai, et al(谭 艳,唐元洪,裴立宅,等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2007, 27(4): 725. [8] Jishi R A, Venkataraman L,Dresselhaus M S, et al. Chem. Phys. Lett., 1993, 209: 77. [9] Kürti J, Kresse G, Kuzmany H. Phys. Rev. B,1998, 58: 8869. [10] Rao A M, Richter E, Shunji B, et al. Science, 1997: 275: 187.