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Author Dai, Jian-Qing ♦ Zhu, Jian-Hui ♦ Xu, Jie-Wang
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY ♦ ABSORPTION ♦ ANTIMONIDES ♦ ASYMMETRY ♦ BERYLLIUM COMPOUNDS ♦ BONDING ♦ CARRIER MOBILITY ♦ COVALENCE ♦ DEPOLARIZATION ♦ EFFECTIVE CHARGE ♦ ELECTRONIC STRUCTURE ♦ FERROELECTRIC MATERIALS ♦ LITHIUM COMPOUNDS ♦ OPTICAL PROPERTIES ♦ PHOTOVOLTAIC EFFECT ♦ POLARIZATION ♦ POTENTIALS ♦ VISIBLE SPECTRA
Abstract The recently discovered hexagonal ABC-type hyperferroelectrics, in which the polarization persists in the presence of the depolarization filed, exhibit a variety of intriguing and potentially useful properties [Garrity et al., Phys. Rev. Lett. 112, 127601 (2014)]. For the existing prototype of LiBeSb, we present detailed first-principles calculations concerning the lattice dynamics, electronic structure, and optical properties. An unstable longitudinal optic mode in the high-symmetry structure and a large polarization of 0.5 C/m{sup 2} in the polar phase are reported, including the remarkable dependence of Born effective charges on structural distortion. Using the HSE06 hybrid functional, we predict that LiBeSb has a small band-gap of 1.5 eV and shows dominant asymmetric covalent bonding character. Importantly, we find that there are remarkable absorptions in the whole visible spectrum. These features, combined with the enhanced carrier mobility, make LiBeSb as well as the whole family of hexagonal ABC-type hyperferroelectrics as promising candidates for ferroelectric photovoltaic materials with large bulk photovoltaic effect in the visible spectrum.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-07-21
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 120
Issue Number 3


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