Vibrational properties of silicene and germanene

作     者：Emilio Scalise Michel Houssa Geoffrey Pourtois B. van den Broek Valery Afanas'ev andAndr Stesmans 

作者机构：Semiconductor Physics Laboratory Department of Physics and Astronomy University of Leuven Celestijnenlaan 200 D B-3001 Leuven Belgium IMEC 75 Kapeldreef B-3001 Leuven Belgium Department of Chemistry PLASMANTresearch group University of Antwerp Universiteitsplein 1 B-2610 Wilrijk-Antwerp Belgium 

出 版 物：《Nano Research》 (纳米研究（英文版）)

年 卷 期：2013年第6卷第1期

页      面：19-28页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 082502[工学-航空宇航推进理论与工程] 081402[工学-结构工程] 081304[工学-建筑技术科学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0813[工学-建筑学] 0814[工学-土木工程] 0825[工学-航空宇航科学与技术] 0702[理学-物理学] 

基　　金：supported by the Research Funds of KU Leuven the European project FET-Open project 

主　　题：振动性能 第一性原理计算 结构屈曲 拉曼光谱 共振喇曼光谱 振动性质 声子模式 纳米带 

摘      要：The structural and vibrational properties of two-dimensional hexagonal silicon (silicene) and germanium (germanene) are investigated by means of first-principles calculations. It is predict that the silicene (germanene) structure with a small buckling of 0.44 Å (0.7 Å) and bond lengths of 2.28 Å (2.44 Å) is energetically the most favorable, and it does not exhibit imaginary phonon mode. The calculated non-resonance Raman spectra of silicene is characterized by a main peak at about 575 cm−1, namely the G-like peak. For germanene, the highest peak is at about 290 cm−1. Extensive calculations on armchair silicene nanoribbons and armchair germanene nanoribbons are also performed, with and without hydrogenation of the edges. The studies reveal other Raman peaks mainly distributed at lower frequencies than the G-like peak which could be attributed to the defects at the edges of the ribbons, thus not present in the Raman spectra of non-defective silicene and germanene. Particularly the Raman peak corresponding to the D mode is found to be located at around 515 cm−1 for silicene and 270 cm−1 for germanene. The calculated G-like and the D peaks are likely the fingerprints of the Raman spectra of the low-buckled structures of silicene and germanene.