Physica E: Low-dimensional Systems and Nanostructures ( IF 3.3 ) Pub Date : 2020-12-16 , DOI: 10.1016/j.physe.2020.114582 A. Yu. Alekseev , D.B. Migas , A.B. Filonov , A.G. Chernykh , V.E. Borisenko , N.V. Skorodumova
By means of ab-initio techniques we have investigated changes in the structure and electronic properties of alkaline-earth metal silicide (Ca2Si, Mg2Si and MgCaSi) nanotubes caused by the curvature-induced effects. It is revealed that the curvature-induced effects can: 1) stabilize Mg2Si nanotubes in a phase, which is metastable for the parent 2D Mg2Si; 2) lead to an energy gain as a result of 2D to nanotube structural transformation in the case of ternary MgCaSi nanotubes; 3) modify the band dispersion and band gaps for nanotubes with the diameters less than 30 Å. In addition, Mg2Si and MgCaSi nanotubes are found to be direct band-gap (0.5–1.2 eV) materials with appreciable oscillator strength of the first direct transitions.
中文翻译:
半导体碱土金属硅化物纳米管中的曲率诱导效应
通过从头算技术,我们研究了由曲率引起的碱土金属硅化物(Ca 2 Si,Mg 2 Si和MgCaSi)纳米管的结构和电子性能的变化。结果表明,曲率引起的效应可以:1)将Mg 2 Si纳米管稳定在一个相中,该相对于母体2D Mg 2 Si是亚稳态的。2)在三元MgCaSi纳米管的情况下,由于2D向纳米管结构的转变而导致能量增加;3)修改直径小于30的纳米管的带分散和带隙。另外,镁2Si和MgCaSi纳米管被发现是直接带隙(0.5–1.2 eV)的材料,其第一次直接跃迁的振荡强度相当大。