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Kumar N, Surovtsev NV, Yunin PA, Ishchenko DV, Milekhin IA, Lebedev SP, Lebedev AA, Tereshchenko OE. Raman scattering spectroscopy of MBE grown thin film topological insulator Bi 2-xSb xTe 3-ySe y. Phys Chem Chem Phys 2024; 26:13497-13505. [PMID: 38651229 DOI: 10.1039/d4cp01169d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
BSTS epitaxial thin film topological insulators were grown using the MBE technique on two different types of substrates i.e., Si (111) and SiC/graphene with Bi0.7Sb1.6Te1.8Se0.9 and Bi0.9Sb1.5Te1.8Se1.1, respectively. The crystallographic properties of BSTS films were investigated via X-ray diffraction, which showed the strongest reflections from the (0 0 l) facets corresponding to the rhombohedral phase. Superior epitaxial growth, homogeneous thickness, smooth surfaces, and larger unit cell parameters were observed for the films grown on the Si substrate. Polarization dependent Raman spectroscopy showed a weak appearance of the Ag mode in cross--polarized geometry. In contrast, a strong Eg mode was observed in both parallel and cross-polarized geometries which correspond to the rhombohedral crystal symmetry of BSTS films. A redshift of Ag and Eg modes was observed in the Raman spectra of BSTS films grown on the Si substrate, compared to those on SiC/graphene, which was directly associated with the unit cell parameter and composition of the films. Raman spectra showed four fundamental modes with asymmetric line shape, and deconvolution of the peaks resulted in additional modes in both the BSTS thin films. The sum of relative ratios of linewidths of fundamental modes (Ag and Eg) of BSTS films grown on Si substrate was lower, indicating a more ordered structure with lower contribution of defects as compared to BSTS film grown on SiC/graphene substrate.
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Affiliation(s)
- N Kumar
- Rzhanov Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
- Faculty of Physics, Tomsk State University, 36 Lenin Ave., Tomsk 634050, Russia
| | - N V Surovtsev
- Institute of Automation and Electrometry, SB, RAS, Novosibirsk, 630090, Russia
| | - P A Yunin
- Institute for Physics of Microstructures, RAS, Afonino, Nizhny Novgorod 603087, Russia
- Faculty of Radiophysics, Lobachevsky State University, Nizhny Novgorod 603950, Russia
| | - D V Ishchenko
- Rzhanov Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
| | - I A Milekhin
- Rzhanov Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
- Novosibirsk State University, Novosibirsk, 630090, Russia
| | - S P Lebedev
- Ioffe Institute, 194021 St. Petersburg, Russia
| | - A A Lebedev
- Ioffe Institute, 194021 St. Petersburg, Russia
| | - O E Tereshchenko
- Rzhanov Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090, Russia.
- Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, SB, RAS, Koltsovo 630559, Russia
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Kurus NN, Kalinin V, Nebogatikova NA, Milekhin IA, Antonova IV, Rodyakina EE, Milekhin AG, Latyshev AV, Zahn DRT. Resonant Raman scattering on graphene: SERS and gap-mode TERS. RSC Adv 2024; 14:3667-3674. [PMID: 38268550 PMCID: PMC10805077 DOI: 10.1039/d3ra07018b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 01/03/2024] [Indexed: 01/26/2024] Open
Abstract
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. In this work, we demonstrate locally enhanced gm-TERS on a monolayer graphene film placed on a plasmonic substrate with specific diameter gold nanodisks. SERS measurements are employed to determine the optimal disk diameter and excitation wavelength for further realization of gm-TERS. A significant local plasmonic enhancement of the main vibrational modes in graphene by a factor of 100 and a high spatial resolution of 10 nm are achieved in the gm-TERS experiment, making gm-TERS chemical mapping possible. By analyzing the gm-TERS spectra of the graphene film in the local area of a nanodisk, the local tensile mechanical strain in graphene was detected, resulting in a split of the G mode into two components, G+ and G-. Using the frequency split in the positions of G+ and G- modes in the TERS spectra, the stress was estimated to be up to 1.5%. The results demonstrate that gap-mode TERS mapping allows rapid and precise characterization of local structural defects in two-dimensional materials on the nanoscale.
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Affiliation(s)
- N N Kurus
- Rzhanov Institute of Semiconductor Physics (SBRAS) Lavrentjev av. 13 Novosibirsk 630090 Russia
| | - V Kalinin
- Novosibirsk State University Pirogov str. 1 Novosibirsk 630090 Russia
| | - N A Nebogatikova
- Rzhanov Institute of Semiconductor Physics (SBRAS) Lavrentjev av. 13 Novosibirsk 630090 Russia
- Novosibirsk State University Pirogov str. 1 Novosibirsk 630090 Russia
| | - I A Milekhin
- Rzhanov Institute of Semiconductor Physics (SBRAS) Lavrentjev av. 13 Novosibirsk 630090 Russia
- Novosibirsk State University Pirogov str. 1 Novosibirsk 630090 Russia
| | - I V Antonova
- Rzhanov Institute of Semiconductor Physics (SBRAS) Lavrentjev av. 13 Novosibirsk 630090 Russia
- Novosibirsk State University Pirogov str. 1 Novosibirsk 630090 Russia
| | - E E Rodyakina
- Rzhanov Institute of Semiconductor Physics (SBRAS) Lavrentjev av. 13 Novosibirsk 630090 Russia
- Novosibirsk State University Pirogov str. 1 Novosibirsk 630090 Russia
| | - A G Milekhin
- Rzhanov Institute of Semiconductor Physics (SBRAS) Lavrentjev av. 13 Novosibirsk 630090 Russia
| | - A V Latyshev
- Rzhanov Institute of Semiconductor Physics (SBRAS) Lavrentjev av. 13 Novosibirsk 630090 Russia
- Novosibirsk State University Pirogov str. 1 Novosibirsk 630090 Russia
| | - D R T Zahn
- Semiconductor Physics and Center for Materials, Architectures and Integration of Nanomembranes (MAIN), Chemnitz University of Technology Reichenhainer Str. 70 D-09107 Chemnitz Germany
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Milekhin IA, Rahaman M, Anikin KV, Rodyakina EE, Duda TA, Saidzhonov BM, Vasiliev RB, Dzhagan VM, Milekhin AG, Latyshev AV, Zahn DRT. Resonant tip-enhanced Raman scattering by CdSe nanocrystals on plasmonic substrates. Nanoscale Adv 2020; 2:5441-5449. [PMID: 36132045 PMCID: PMC9417628 DOI: 10.1039/d0na00554a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 10/02/2020] [Indexed: 06/15/2023]
Abstract
Tip-enhanced Raman scattering (TERS) has recently emerged as a powerful technique for studying the local properties of low dimensional materials. Being a plasmon driven system, a dramatic enhancement of the TERS sensitivity can be achieved by an appropriate choice of the plasmonic substrate in the so-called gap-mode configuration. Here, we investigate the phonon properties of CdSe nanocrystals (NCs) utilizing gap-mode TERS. Using the Langmuir-Blodgett technique, we homogeneously deposited submonolayers of colloidal CdSe NCs on two different nanostructured plasmonic substrates. Amplified by resonant gap-mode TERS, the scattering by the optical phonon modes of CdSe NCs is markedly enhanced making it possible to observe up to the third overtone of the LO mode reliably. The home-made plasmonic substrates and TERS tips allow the analysis of the TERS images of CdSe phonon modes with nanometer spatial resolution. The CdSe phonon scattering intensity is strongly correlated with the local electromagnetic field distribution across the plasmonic substrates.
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Affiliation(s)
- I A Milekhin
- Semiconductor Physics, Chemnitz University of Technology D-09107 Chemnitz Germany
| | - M Rahaman
- Semiconductor Physics, Chemnitz University of Technology D-09107 Chemnitz Germany
| | - K V Anikin
- A.V. Rzhanov Institute of Semiconductor Physics Novosibirsk Russia
| | - E E Rodyakina
- Novosibirsk State University Novosibirsk Russia
- A.V. Rzhanov Institute of Semiconductor Physics Novosibirsk Russia
| | - T A Duda
- A.V. Rzhanov Institute of Semiconductor Physics Novosibirsk Russia
| | - B M Saidzhonov
- Department of Chemistry, Moscow State University Moscow Russia
- Department of Material Science, Moscow State University Moscow Russia
| | - R B Vasiliev
- Department of Chemistry, Moscow State University Moscow Russia
- Department of Material Science, Moscow State University Moscow Russia
| | - V M Dzhagan
- V.E. Lashkaryov Institute of Semiconductor Physics UA-03028 Kiev Ukraine
| | - A G Milekhin
- Novosibirsk State University Novosibirsk Russia
- A.V. Rzhanov Institute of Semiconductor Physics Novosibirsk Russia
| | - A V Latyshev
- Novosibirsk State University Novosibirsk Russia
- A.V. Rzhanov Institute of Semiconductor Physics Novosibirsk Russia
| | - D R T Zahn
- Semiconductor Physics, Chemnitz University of Technology D-09107 Chemnitz Germany
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Milekhin IA, Anikin KV, Rahaman M, Rodyakina EE, Duda TA, Saidzhonov BM, Vasiliev RB, Dzhagan VM, Milekhin AG, Batsanov SA, Gutakovskii AK, Latyshev AV, Zahn DRT. Resonant plasmon enhancement of light emission from CdSe/CdS nanoplatelets on Au nanodisk arrays. J Chem Phys 2020; 153:164708. [PMID: 33138402 DOI: 10.1063/5.0025572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Semiconducting nanoplatelets (NPLs) have attracted great attention due to the superior photophysical properties compared to their quantum dot analogs. Understanding and tuning the optical and electronic properties of NPLs in a plasmonic environment is a new paradigm in the field of optoelectronics. Here, we report on the resonant plasmon enhancement of light emission including Raman scattering and photoluminescence from colloidal CdSe/CdS nanoplatelets deposited on arrays of Au nanodisks fabricated by electron beam lithography. The localized surface plasmon resonance (LSPR) of the Au nanodisk arrays can be tuned by varying the diameter of the disks. In the case of surface-enhanced Raman scattering (SERS), the Raman intensity profile follows a symmetric Gaussian shape matching the LSPR of the Au nanodisk arrays. The surface-enhanced photoluminescence (SEPL) profile of NPLs, however, follows an asymmetric Gaussian distribution highlighting a compromise between the excitation and emission enhancement mechanisms originating from energy transfer and Purcell effects. The SERS and SEPL enhancement factors depend on the nanodisk size and reach maximal values at 75 and 7, respectively, for the sizes, for which the LSPR energy of Au nanodisks coincides with interband transition energies in the semiconductor platelets. Finally, to explain the origin of the resonant enhancement behavior of SERS and SEPL, we apply a numerical simulation to calculate plasmon energies in Au nanodisk arrays and emission spectra from NPLs in such a plasmonic environment.
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Affiliation(s)
- I A Milekhin
- Semiconductor Physics, Chemnitz University of Technology, Chemnitz, Germany
| | - K V Anikin
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - M Rahaman
- Semiconductor Physics, Chemnitz University of Technology, Chemnitz, Germany
| | - E E Rodyakina
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - T A Duda
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - B M Saidzhonov
- Department of Chemistry, Moscow State University, Moscow, Russia
| | - R B Vasiliev
- Department of Chemistry, Moscow State University, Moscow, Russia
| | - V M Dzhagan
- V.E. Lashkaryov Institute of Semiconductor Physics, UA-03028 Kiev, Ukraine
| | - A G Milekhin
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - S A Batsanov
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - A K Gutakovskii
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - A V Latyshev
- A.V. Rzhanov Institute of Semiconductor Physics, Novosibirsk, Russia
| | - D R T Zahn
- Semiconductor Physics, Chemnitz University of Technology, Chemnitz, Germany
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