PLASMON-ENHANCED VIBRATIONAL; SPECTROSCOPY OF SEMICONDUCTOR NANOCRYSTALS
A.G. Milekhin1,2, T.A. Duda1, E.E. Rodyakina1,2, K.V. Anikin1, S.A. Kuznetsov2,3, I.A. Milekhin4, D.R.T. Zahn4, A.V. Latyshev1,2
1Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Science, Technological and Design Institute of Applied Microelectronics “TDIAM”, Novosibirsk, Russia
4Semiconductor Physics, Technische Universitaet Chemnitz, Chemnitz, Germany
Keywords: фононы, локализованный плазмонный резонанс, нанокристаллы, ИК-спектроскопия, комбинационное рассеяние света, phonons, localized surface plasmon resonance, nanocrystals, IR spectroscopy, Raman scattering
Abstract
This paper provides an overview of recent results and new data on the study of the optical response of semiconductor nanocrystals obtained using plasmon-enhanced optical spectroscopies, including the surface-enhanced Raman scattering (SERS) and surface-enhanced IR absorption (SEIRA). These methods are based on enhancement of the phonon response of semiconductor nanocrystals placed in the field of localized surface plasmon resonance (LSPR) of metal nanostructures. Due to a proper choice of a certain morphology of metal nanostructures, the LSPR energy coincides with the laser excitation energy and/or the energy of optical phonons in nanocrystals. The resonant conditions provide a significant increase in local electric fields and, as a result, a sharp increase in the Raman signal and IR absorption at the frequencies of surface optical phonons of nanocrystals. Enhancement of the optical response makes it possible not only to detect monolayer coatings of nanocrystals, but also to study their crystal structure, phase and elemental composition, and internal mechanical stresses. Utilization of the Raman spectroscopy in combination with atomic force microscopy has opened up new possibilities for analyzing the vibrational and electronic spectra of nanocrystals with nanometer spatial resolution.
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