Anisotropic phonon responses of 2D NbOX2 (X<b>=</b>Cl, Br, I) under uniaxial tensile strain
Abstract
The van der Waals crystal NbOX2 (X = Cl, Br, I) has recently attracted much attention due to its remarkable in-plane anisotropy and substantial second-order nonlinear optical response. Moreover, the importance of modulating its physical properties through strain has become increasingly prominent. Herein, we investigate the anisotropic phonon response of NbOX2 along various crystallographic directions under uniaxial tensile strain by Raman spectroscopy. The results show that opposing frequency shifts manifest in the Raman modes when uniaxial tensile strain is applied either parallel or perpendicular to the polar axis, and the highest frequency peak, P5, shows significant blue or red shifts. Density functional theory calculation results are consistent with the observed Raman shifts under strain. The change in Nb–O bond length is the main reason for the significant blue shift of P5. The anisotropic and pronounced frequency shifts of NbOX2 under strain can serve as sensitive indicators for strain modulation, offering insights for potential applications such as flexible optoelectronic devices and strain sensors.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (13)
Xiaoyue Fan
Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics and Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology , Beijing 100081,
Ziling Shen
Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics and Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology , Beijing 100081,
Deng Hu
Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics and Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology 1 , Beijing 100081,
Youning Liu
Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics and Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology 1 , Beijing 100081,
Tianhong Tang
Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics and Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology 1 , Beijing 100081,
Wenchen Yang
Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement, Ministry of Education, School of Physics and Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, Beijing Institute of Technology , Beijing 100081,
Haiyang Liu
Shenzhen Key Laboratory of Biomolecular Assembling and Regulation, Department of Neuroscience, School of Life Sciences, Southern University of Science and Technology
Yuxin Song
Qinsheng Wang
Baoli Liu
Education and Research Department, Beijing Changier Education Foundation
Zhiwei Wang
International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry and College of Chemistry
Jin-Jian Zhou
Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology 2 , Beijing 100081,
Gang Wang