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Research Highlight

Simulations Guide Experiments in Understanding Strain-Dependent Raman Scattering of Black Phosphorus

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For the angle-resolved Raman characterization of few layer BP under uniaxial tensile strains, first-principles density functional theory (DFT) calculations validated experimental data, and revealed the opposite behaviors of three Raman modes under the uniaxial zigzag and armchair strains. The Poisson’s ratio was found to be the driving force.

Scientific Achievement

First-principles calculations and Raman scattering measurements reveal that the anisotropic Poisson’s ratio in few-layer black phosphorus (BP) underlies discrepancies reported in literature for trends of Raman shifts with respect to uniaxial strains.

Significance and Impact

A clear understanding of the mechanism for the strain-induced Raman shifts means that it can be used to correlate properties; a step for enabling few-layer black phosphorus as a key candidate for electronics and photonics applications.

Research Details

– Phonon and Raman simulations were performed at CNMS to understand the behaviors of Raman modes in BP under strain.

– Raman measurements were done at UT-Austin to study the phonon response of BP under strain.

W. Zhu, L. Liang, R. Roberts, J.-F. Lin, and D. Akinwande, "Anisotropic electron − phonon interactions in angle-resolved Raman study of strained black phosphorus," ACS Nano 12, 12512−12522 (2018).   DOI:10.1021/acsnano.8b06940