CC BY
10ALT'22
LASER DIAGNOSTICS AND SPECTROSCOPY
LD-I-4
Near-field Optical and IR Spectroscopies of Semiconductor Nanostructures
A.G. Milekhin1, I.A. Milekhin2, N.N. Kurus1, L.S. Basalaeva1, R.B.Vasiliev3, K.V. Anikin1, V.G. Mansurov1,
K.S. Zhuravlev1, A.V. Latyshev14, D.R.T. Zahn2
1 A.V. Rzhanov Institute of Semiconductor Physics, 630090, Novosibirsk, Lavrentjev av. 13, Russia 2 Semiconductor Physics, Chemnitz University of Technology, D-09107 Chemnitz, Germany 3 Department of Material Science, Moscow State University, Moscow, Russia 4 Novosibirsk State University, Novosibirsk, 630090, Pirogov str., 1, Russia
Tip-Enhanced Raman scattering, photoluminescence, and nano-InfraRed (TERS, TEPL, and nano-IR) spectroscopies were successfully applied to study the phonon and electron spectra of 2D and 1D single nanostructures with the spatial resolution much below diffraction limit.
TERS imaging by optical phonons in single 2D nanostructures including graphene, colloidal core/shell CdSe/CdS nanoplatelets, and MoS2 monolayers placed in the gap between the TERS tip apex and plasmonic substrate, which allows determination of nanostructure size and shape, structural defects, mechanical strain, and local electromagnetic field enhancement, is demonstrated. Near-field photoluminescence or TEPL from MoS2 and WS2 monolayer islands grown on a Si substrate reveals local variation of exciton PL energy and intensity depending on the number of monolayers and the presence of structural defects.
TERS by surface optical (SO) phonons in AlN nanoclusters grown by molecular beam epitaxy of a Si substrate and nanocolumns placed on an Au surface was observed. The TERS image of a single wurtzite AlN nanocluster with a size of about 300 nm shows its hexagonal shape. TERS taken from AlN nanocolumns with a diameter and height of about 200 and 50 nm, respectively, with different light polarizations with respect to the nanocolumn axes demonstrates different images. The origin of the changes in TERS images upon the light polarization is discussed.
We also present the comparative results of Raman data with the hyperspectral infrared nanoimages of AlN nanostructures based on Fourier transform nano-IR spectroscopy. IR nanospectroscopy allows the studying the spatial localization of surface optical phonon modes originated from optical phonon localized near the edges of hexagonal AlN nanoclusters with different symmetries.
This work was supported by the Russian Science Foundation (project 22-12-00302).
