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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

TEMPERATURE-DEPENDENT CHARACTERISTICS OF RAMAN SCATTERING ENHANCEMENT INDUCED BY AU NANOPATTERNS

Get access (open in a dialog) DOI: 10.1615/IHTC16.mtr.021906
pages 5743-5747

要約

Surface-enhanced Raman scattering induced by metallic nanostructures has attracted much attention due to its great potential in bio-sensing and other optical application. In these applications, noticeable light absorption and the resultant temperature rise, relevant to optical/thermal coupling could be a serious issue affecting the sensitivity and stability in optical sensing. However, the underlying physical mechanism still remains as unexplored. In this work, the enhancement of Raman signal from a silicon wafer patterned with Au nanorods array is experimentally investigated for its temperature-dependent characteristics and are interpreted by electromagnetic simulations. The Au nanopatterns show significant enhancement on silicon Raman signal over the temperature range of 293 to 424 K. As temperature is increased by 130 K, the Raman enhancement factor is decreased by 10.2%. The Raman frequency of silicon with and without Au nanopatterns decreases similarly with the increase of temperature. The decreasing ratio of Raman frequency shift with increment of laser power for Au decorating silicon is three more times than that for bare silicon. It indicates that there is an additional heat effect on silicon from Au nanopatterns which may results in decrease of 3% in Raman enhancement factor. Numerical simulations are performed by using of finite-difference time-domain method to determine the distribution of electromagnetic field around Au nanorods. The predicted enhancement factor is decreased by 28.3%, agreeing well with the experimental data. The findings in this work would help understand the Raman enhancement decreasing at elevated temperatures, especially for photovoltaic applications.