TY - JOUR

T1 - Density-Functional Study of the Si/SiO2 Interfaces in Short-Period Superlattices: Vibrational States and Raman Spectra

AU - Смирнов, Михаил Борисович

AU - Рогинский, Евгений Михайлович

AU - Орешонков, Александр

AU - Савин, Александр Владимирович

AU - Панькин, Дмитрий Васильевич

PY - 2023/8/4

Y1 - 2023/8/4

N2 - Raman spectroscopy has proven its effectiveness as a highly informative and sensitive method for the nondestructive analysis of layered nanostructures and their interfaces. However, there is a lack of information concerning the characteristic phonon modes and their activity in Si/SiO2 nanostructures. In order to overcome this problem, the phonon states and Raman spectra of several Si/SiO2 superlattices (SL) with layer thicknesses varied within 0.5–2 nm are studied using DFT-based computer modeling. Two types of structures with different interfaces between crystalline silicon and SiO2 cristobalite were studied. A relationship between the phonon states of heterosystems and the phonon modes of the initial crystals was established. Estimates of the parameters of deformation potentials are obtained, with the help of which the shifts of phonon frequencies caused by elastic strains in the materials of the SL layers are interpreted. The dependence of intense Raman lines on the SL structure has been studied. Several ways have been proposed to use this information, both for identifying the type of interface and for estimating the structural parameters. The obtained information will be useful for the spectroscopic characterization of the silicon/oxide interfaces.

AB - Raman spectroscopy has proven its effectiveness as a highly informative and sensitive method for the nondestructive analysis of layered nanostructures and their interfaces. However, there is a lack of information concerning the characteristic phonon modes and their activity in Si/SiO2 nanostructures. In order to overcome this problem, the phonon states and Raman spectra of several Si/SiO2 superlattices (SL) with layer thicknesses varied within 0.5–2 nm are studied using DFT-based computer modeling. Two types of structures with different interfaces between crystalline silicon and SiO2 cristobalite were studied. A relationship between the phonon states of heterosystems and the phonon modes of the initial crystals was established. Estimates of the parameters of deformation potentials are obtained, with the help of which the shifts of phonon frequencies caused by elastic strains in the materials of the SL layers are interpreted. The dependence of intense Raman lines on the SL structure has been studied. Several ways have been proposed to use this information, both for identifying the type of interface and for estimating the structural parameters. The obtained information will be useful for the spectroscopic characterization of the silicon/oxide interfaces.

KW - DFT modelling

KW - Raman spectra

KW - cristobalite

KW - interface

KW - silicon

KW - superlattice

UR - https://www.mendeley.com/catalogue/1ee49079-d9c9-35b6-abe6-f49ea3f94d13/

U2 - 10.3390/photonics10080902

DO - 10.3390/photonics10080902

M3 - Article

VL - 10

JO - Photonics

JF - Photonics

SN - 2304-6732

IS - 8

M1 - 902

ER -