Nanoscale deformations and corrugations occur in graphene-like two-dimensional materials during their incorporation into hybrid structures and real devices, such as sensors based on surface-enhanced Raman scattering (SERS-based sensors). The structural features mentioned above are known to affect the electronic properties of graphene, thus highly sensitive and high-resolution techniques are required to reveal and characterize arising local defects, mechanical deformations, and phase transformations. In this study, we demonstrate that gap-mode tip-enhanced Raman Scattering (gm-TERS), which offers the benefits of structural and chemical analytical methods, allows variations in the structure and mechanical state of a two-dimensional material to be probed with nanoscale spatial resolution.
View Article and Find Full Text PDFWe demonstrate local phonon analysis of single AlN nanocrystals by two complementary imaging spectroscopic techniques: tip-enhanced Raman scattering (TERS) and nano-Fourier transform infrared (nano-FTIR) spectroscopy. Strong surface optical (SO) phonon modes appear in the TERS spectra with their intensities revealing a weak polarization dependence. The local electric field enhancement stemming from the plasmon mode of the TERS tip modifies the phonon response of the sample, making the SO mode dominate over other phonon modes.
View Article and Find Full Text PDFTwenty-four potato (Solanum tuberosum L.) varieties differing in ripening groups (early, middle-early, and mid-season-ripening) were studied. Potatoes were grown under the conditions of the Middle Volga region of Russia in 2019-2021.
View Article and Find Full Text PDFThis work presents an overview of the latest results and new data on the optical response from spherical CdSe nanocrystals (NCs) obtained using surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS). SERS is based on the enhancement of the phonon response from nanoobjects such as molecules or inorganic nanostructures placed on metal nanostructured substrates with a localized surface plasmon resonance (LSPR). A drastic SERS enhancement for optical phonons in semiconductor nanostructures can be achieved by a proper choice of the plasmonic substrate, for which the LSPR energy coincides with the laser excitation energy.
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