Polaronic effects in monolayer black phosphorus on polar substrates

Article

关键词: PHONON INTERACTION;    BAND-GAP;    GRAPHENE;    HETEROSTRUCTURES;    SEMICONDUCTOR;    EXFOLIATION;    SCATTERING;    PROPERTY;    MOBILITY;    LAYERS;   

DOI  :  10.1103/PhysRevB.93.085417

来源: SCIE

【 摘 要 】

We investigate the effect of charge carrier interaction with surface optical phonons on the band properties of monolayer black phosphorus induced by polar substrates. We develop an analytical method based on the Lee-Low-Pines theory to calculate the spectrum of Frohlich type continuum Hamiltonian in the long-wavelength limit. We examine the modification of a band gap and renormalization of effective masses due to the substrate-related polaronic effect. Our results show that an energy gap in supported monolayer black phosphorus is enlarged depending on a particular substrate and the interlayer distance z. Among the substrate considered, the largest gap broadening at z = 2.5 angstrom is observed for the Al2O3 substrate, which is found to be similar to 50 meV. Carrier-phonon coupling also renormalizes the effectivemasses which is more pronounced along the zigzag direction. Anisotropy of the effective masses becomes stronger by the influence of the polaronic effect corresponding to direction-dependent carrier-phonon coupling. We conclude that substrate phonons have a non-negligible effect on the static band properties of monolayer black phosphorus, which may be further exploited in its experimental and theoretical studies.

【 授权许可】

Free