Correlation analysis of vibration modes in physical vapour deposited Bi2Se3 thin films probed by the Raman mapping technique
Journal article, 2021
In this work, the Raman spectroscopy mapping technique is used for the analysis of mechanical strain in Bi2Se3 thin films of various (3-400 nm) thicknesses synthesized by physical vapour deposition on amorphous quartz and single-layer graphene substrates. The evaluation of strain effects is based on the correlation analysis of in-plane (E2g) and out-of-plane (A21g) Raman mode positions. For Bi2Se3 films deposited on quartz, experimental datapoints are scattered along the line with a slope of similar to 0.85, related to the distribution of hydrostatic strain. In contrast to quartz/Bi2Se3 samples, for graphene/Bi2Se3 heterostructures with the same thicknesses, an additional negative slope of similar to-0.85, which can be associated with the distribution of the in-plane (a-b) biaxial tensile strain due to the film-substrate lattice mismatch, is observed. The algorithm of phonon deformation potential (PDP) calculation based on the proposed strain analysis for the 3 nm thick Bi2Se3 film deposited on the graphene substrate, where the strain is considered to be coherent across the thickness, is demonstrated. The PDPs for biaxial in-plane strain of the Bi2Se3 3 nm film in in-plane and out-of-plane modes are equal to -7.64 cm(-1)/% and -6.97 cm(-1)/%, respectively.
Author
K. A. Niherysh
Belarusian State University of Informatics and Radioelectronics
University of Latvia
J. Andzane
University of Latvia
M. M. Mikhalik
Belarusian State University of Informatics and Radioelectronics
S. M. Zavadsky
Belarusian State University of Informatics and Radioelectronics
P. L. Dobrokhotov
National Research Nuclear University
Floriana Lombardi
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
S. L. Prischepa
Belarusian State University of Informatics and Radioelectronics
National Research Nuclear University
Komissarov
Belarusian State University of Informatics and Radioelectronics
National Research Nuclear University
D. Erts
University of Latvia
Nanoscale Advances
25160230 (eISSN)
Vol. 3 22 6395-6402High Frequency Topological Insulator devices for Metrology (HiTIMe)
European Commission (EC) (EC/H2020/766714), 2018-02-01 -- 2022-01-31.
Subject Categories
Other Physics Topics
Other Materials Engineering
Condensed Matter Physics
DOI
10.1039/d1na00390a