Electron–phonon dynamics in 2D carbon based-hybrids XC (X  =  Si, Ge, Sn)

Abstract

The effect of the presence of electron-phonon (e-ph) coupling in the S iC, GeC and S nC hybrids is studied in the framework of the ab initio perturbation theory. The electronic bang gap thermal dependence reveals a normal monotonic decrease in the S iC and GeC semiconductors, whereas S nC exhibits an anomalous behavior. The electron line widths were evaluated and the contributions of acoustic and optical phonon modes to the imaginary part of the self-energy were determined. It has been found that the e-ph scattering rates are globally controlled by the out-of-plane acoustic transverse mode ZA in SiC while both ZA and ZO are overriding in GeC. In S nC, the out-of-plane transverse optical mode ZO is the most dominant. The relaxation lifetime of the photo-excited electrons shows that the thermalization of the hot carrier occurs at 90 f s, 100 f s and 120 f s in S iC, GeC and S nC respectively. The present study properly describes the subpicosecond time scale after sunlight illumination using an approach that requires no empirical data. The results make the investigated structures suitable for providing low cost and high-performance optical communication and monitoring applications using 2D materials.

Germanium‐based monoelemental and binary two‐dimensional materials: Theoretical and experimental investigations and promising applications

“…Schematic illustration of Ge‐IVA binary compounds. (A) Atomic structure of planar hybrids GeC with a = 3.245 Å and d = 1.965 Å. Reproduced with permission 153 . Copyright 2019, IOP Publishing Ltd. (B) The geometric structures of GeX (X: Si, Sn, Pb) sheets.…”

“…Further, 2D Ge‐based binary compounds, such as GeC, GeS, GeS 2 , and GeSe 2 , have a direct bandgap of over 2.0 eV, and the gap value can be adjusted via electric field and strain application, chemical modification, doping, nanopatterning, and so on. Therefore, these materials can be used in blue and purple LEDs and optical devices 153,179,184,425 …”

“…A large number of theoretical calculations have been performed to determine the possible structure of 2D Ge-IV binary compounds. The most studied structure has an alternative arrangement of Ge atom with another atom at an atomic ratio of 1:1, 153,154 as shown in Figure 9A,B. The recently published calculation results related to the stable structures and basic electronic properties of 2D GeC, GeSi, GeSn, and GePb are summarized in Table 2.…”

Domain Walls in Topological Tri-hinge Matter

“…Graphene is the star member of the honeycomb lattices family exhibiting ultrathin thickness and characterized by intriguing properties [31,32]. Other elements of group-IV, such as silicene, germanene, stanene, and their hybrids, namely SiC, GeC, SnSi, etc, have also emerged to widespread the list of 2D hexagonal materials [33][34][35][36].…”

Magnetic Skyrmions: Theory and Applications

“…One possible route to achieve this goal is the formation of topological protected skyrmions in certain 2D magnetic materials. To induce magnetic order and tune DMIs in 2D crystal structures, their centrosymmetric should first be broken using some efficient ways such a (i) generate one-atom thick hybrids where atoms are mixed in an alternating manner [39][40][41], (ii) apply bias voltage or strain [42][43][44], (iii) insert adsorbents, impurities and defects [45][46][47]. In graphene-like materials, fluorine chemisorption is an exothermic adsorption that gives rise to stable 2D structures [48] and to long-range magnetism [49,50].…”