Anisotropic Electron–Phonon Interactions in Angle-Resolved Raman Study of Strained Black Phosphorus
- The Univ. of Texas, Austin, TX (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Few-layer black phosphorus (BP) with an in-plane puckered crystalline structure has attracted intense interest for strain engineering due to both its significant anisotropy in mechanical and electrical properties and its high intrinsic strain limit. Here, we investigated the phonon response of few layer BP under uniaxial tensile strain (~7%) with in situ polarized Raman spectroscopy. Together with the first-principles density functional theory (DFT) analysis, the anisotropic Poisson’s ratio in few-layer BP was verified as one of the primary factors that caused the large discrepancy in the trend of reported Raman frequency shift for strained BP, armchair (AC) direction in particular. By carefully including and excluding the anisotropic Poisson’s ratio in the DFT emulations, we rebuilt both trends reported for Raman mode shifts. Furthermore, the angle-resolved Raman spectroscopy was conducted in situ under tensile strain for systematic investigation of the in-plane anisotropy of BP phonon response. The experimentally observed thickness and crystallographic orientation dependence is elaborated using DFT theory as having a strong correlation between the strain-perturbated electronic-band structure and the phonon vibration modes. Furthermore, this study provides insight, both experimentally and theoretically, for the complex electron–phonon interaction behavior in strained BP, which enables diverse possibilities for the strain engineering of electrical and optical properties in BP and similar two-dimensional nanomaterials.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1489574
- Journal Information:
- ACS Nano, Vol. 12, Issue 12; ISSN 1936-0851
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Raman Activity of Multilayer Phosphorene under Strain
|
journal | December 2019 |
Thermal Transport in 2D Semiconductors—Considerations for Device Applications
|
journal | August 2019 |
Anisotropic thermal conductivity in direction-specific black phosphorus nanoflakes
|
journal | September 2019 |
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