Influence of crystal size on the electron–phonon coupling in ZnO nanocrystals investigated by Raman spectroscopy |
| |
| Institution: | 1. Department of Physics, Motilal Nehru National Institute of Technology, Allahabad, India;2. Center for Functional Materials and Nanomolecular Science, Jacobs University Bremen, 28759 Bremen, Germany;3. Department of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042, India;4. Department of Applied Chemistry, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042, India;5. Department of Physics, The LNM Institute of Information Technology, Jaipur-302031, India;1. Department of Oral and Maxillofacial Surgery, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China;2. Department of Oral and Maxillofacial Surgery, HaiNan General Hospital, HaiNan, China;3. Department of Oral and Maxillofacial Surgery, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China;1. Department of Physics, Motilal Nehru National Institute of Technology, Allahabad 211004, India;2. Department of Physics, National Institute of Technology, Hazratbal, Srinagar 190006, India;3. Department of Physics, The LNM Institute of Information Technology, Jaipur 302031, India;1. Departamento de Física, CCET, Universidade Federal do Maranhão, 65085-580, São Luís, MA, Brazil;2. Departamento de Química, CCET, Universidade Federal do Maranhão, 65085-580, São Luís, MA, Brazil;3. Departamento de Física, Universidade Federal do Ceará, Campus do Pici, 60455-760, Fortaleza, CE, Brazil;4. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, United States;5. Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA 94720-1760, United States;6. Department of Physics, University of California Berkeley, Berkeley, CA 94720-7300, United States;1. Hebei Key Lab of Optic-Electronic Information and Materials, The College of Physics Science and Technology, Hebei University, Baoding 071002, China;2. Department of Chemistry, Renmin University of China, Beijing 100872, China |
| |
| Abstract: | We have synthesized ZnO nanocrystals of different sizes (25–41 nm) using the sol–gel method and characterized them using different techniques such as: transmission electron microscopy (TEM) and X-ray diffraction (XRD). Raman spectra of different sizes of ZnO nanocrystals were recorded at two excitation wavelengths, 514 and 647 nm, in the spectral range 300–1200 cm?1. The vibrational modes were assigned on the basis of group theory analysis. The influence of mean crystallite size on the strength of the electron–phonon coupling is experimentally estimated by the variation of relative intensities of second order Raman band and the first order Raman band for ZnO nanocrystals of different sizes. We found that the intensity ratio of the 2E2 and 1E2 Raman bands decreases almost linearly for both excitation wavelengths with decreasing crystallite size, which reveals that the Fröhlich interaction plays a dominant role in the electron–phonon coupling of the ZnO nanocrystals. |
| |
| Keywords: | ZnO Nanocrystals Raman spectroscopy Electron–phonon coupling Fröhlich interaction |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
