Tight-binding piezoelectric theory and electromechanical coupling correlations for transition metal dichalcogenide monolayers

Article

关键词: ATOMIC-LAYER MOS2;    ELECTRICAL-CONDUCTIVITY;    GRAPHENE;    POLARIZATION;    FERROELECTRICITY;    OPTOELECTRONICS;    SEMICONDUCTORS;    MECHANICS;    BANDGAP;    FIELD;   

DOI  :  10.1103/PhysRevB.98.125402

来源: SCIE

【 摘 要 】

The lack of inversion symmetry in semiconducting transition metal dichalcogenide monolayers (TMDMs) enables a considerable intrinsic piezoelectricity, which opens prospects for atomically thin piezotronics and optoelectronics. Here, based on the tight-binding (TB) approach and Berry phase expression for electronic polarization difference, we establish an atomic-scale TB theory for demonstrating piezoelectric physics in TMDMs. Using the TB piezoelectric theory, we predict the electronic Grfineisen parameter (EGP), which measures the electron-phonon couplings for TMDMs. By virtue of the constructed analytical piezoelectric model, we further reveal the correlation between the electronic contribution to piezoelectric coefficients and strain-induced pseudomagnetic gauge field (PMF). These predicted EGP and PMF for TMDMs are experimentally testable, and hence the TB piezoelectric model is an alternative theoretical framework for calculating electron-phonon interactions and PMF.

【 授权许可】

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