Talwar, D.N.; Becla, P. Evaluating Phonon Characteristics by Varying the Layer and Interfacial Thickness in Novel Carbon-Based Strained-Layer Superlattices. Solids2023, 4, 287-303.
Talwar, D.N.; Becla, P. Evaluating Phonon Characteristics by Varying the Layer and Interfacial Thickness in Novel Carbon-Based Strained-Layer Superlattices. Solids 2023, 4, 287-303.
Talwar, D.N.; Becla, P. Evaluating Phonon Characteristics by Varying the Layer and Interfacial Thickness in Novel Carbon-Based Strained-Layer Superlattices. Solids2023, 4, 287-303.
Talwar, D.N.; Becla, P. Evaluating Phonon Characteristics by Varying the Layer and Interfacial Thickness in Novel Carbon-Based Strained-Layer Superlattices. Solids 2023, 4, 287-303.
Abstract
Systematic results of lattice dynamical calculation are reported for the novel (SiC)m/(GeC)n superlattices (SLs) by exploiting a modified-linear chain model (M-LCM) and a realistic rigid-ion- model (RIM). By employing the bond polarizability method in the framework of M-LCM, we have simulated Raman intensities for the graded (SiC)10-D/(Si0.5Ge0.5C)D/(GeC)10-D/(Si0.5Ge0.5C)D SLs by carefully integrating interfacial layer thickness D (≡ 0, 1, 2, 3 monolayers (MLs)). The variation of D has initiated considerable up (down) shifts of GeC-, (SiC)-like Raman peaks in the middle of the optical phonon frequency region. With D = 3 MLs, the maximum energy shift (by ~ 47 cm-1) of SiC-like modes has caused substantial changes in the Raman intensity profiles linked to the localization of atomic displacements at the interfacial transition regions. This effect can be considered as a vital tool for authenticating the interfacial structures in technologically important SLs. By using a RIM, we have reported SL phonon dispersions along the growth [001] as well as in the plane [100], [110] perpendicular to the growth. Our simulations of phonons in the acoustic mode region have not only confirmed the formation of minigaps at the zone center and zone edges but also provided evidence of anti-crossing and phonon confinement. Besides examining angular dependence of zone-center optical modes, we have also discussed phonon folding, confinement and anisotropic behavior in (SiC)m/(GeC)n SLs.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
