Research on characteristic properties of ASiGe nanoribbons materials for nanoelectronics and optoelectronics applications

This article presents the properties of armchair SiGe nanoribbon (ASiGeNR) configurations with varying ribbon widths. Using the Vienna Ab initio Simulation Package calculation program, several basic properties-such as electronic band structure, density of states, charge density distribution, real and imaginary parts of the dielectric functions, joint density of states (JDOS) and the optical absorption and reflection rates according to the energy of incident light-were investigated and evaluated. The electronic band structure was computed using both the generalized gradient approximation Perdew-Burke-Ernzerhof and HSE06 methods. The results show that the ASiGeNR configurations have a direct bandgap, ranging from a minimum of 0.0889 to a maximum of 0.7528 eV, depending on the number of atoms along the nanoribbon width, with the bandgap opening at the Γ point. There is a hybridization of sp² and sp³ orbitals in the ASiGeNRs, with the σ bonds being relatively stronger than the π bonds. ASiGeNR systems allow electromagnetic waves to pass through, primarily in the <i>z</i>-direction. The energy levels and directions in which the ASiGeNR structure absorbs or disperses the most energy occur between 2 and 4 eV in the <i>y</i>- and <i>z</i>-directions. The real part of the dielectric function varies significantly across the different structures, with the most noticeable change occurring in the <i>z</i>-direction. The ASiGeNR6 structure exhibits the highest absorption peak, which gradually decreases in the subsequent structures. The imaginary part of the dielectric function tends to peak at photon energies below 4 eV, indicating strong interaction between light and the material structures within this energy range. This suggests that changes in nanoribbon width significantly affect the optical properties of the material. The JDOS results align with the optical absorption spectrum, with peaks in JDOS corresponding to peaks in the optical absorption spectrum.