Electron-acoustic-phonon interaction in core/shell Ge/Si and Si/Ge nanowires

Article

关键词: RADIAL BREATHING MODE;    CORE-SHELL NANOWIRES;    THERMAL-CONDUCTIVITY;    SILICON NANOWIRES;    SI;    GE;    SEMICONDUCTORS;    CONFINEMENT;    BAND;   

DOI  :  10.1103/PhysRevB.95.155317

来源: SCIE

【 摘 要 】

General expressions for the electron- and hole-acoustic-phonon deformation potential Hamiltonians (HE-DP) are derived for the case of Ge/Si and Si/Ge core/shell nanowire structures (NWs) with circular cross section. Based on the short-range elastic continuum approach and on derived analytical results, the spatial confinement effects on the phonon displacement vector, the phonon dispersion relation and the electron- and hole-phonon scattering amplitudes are analyzed. It is shown that the acoustic displacement vector, phonon frequencies and HE-DP present mixed torsional, axial, and radial components depending on the angular momentum quantum number and phonon wave vector under consideration. The treatment shows that bulk group velocities of the constituent materials are renormalized due to the spatial confinement and intrinsic strain at the interface. The role of insulating shell on the phonon dispersion and electron-phonon coupling in Ge/Si and Si/Ge NWs are discussed.

【 授权许可】

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