Predicting a Novel Phase of 2D SiTe2
Predicting a Novel Phase of 2D SiTe2
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DOI：
10.1021/acsomega.0c02048
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发表时间：
2020-07-14
期刊：
影响因子：
4.1
通讯作者：
Shen, Xiao
中科院分区：
文献类型：
--
作者：
Bhattarai, Romakanta;Shen, Xiao
层状IV-VI 2化合物通常以CdI 2结构存在。使用演化算法和第一性原理计算，我们预测一种新的层状结构的碲化硅（SiTe 2），是更稳定的CdI 2相。该结构在其本体形式中具有三斜晶胞。原子排列表明Si原子形成四面体键的倾向和Te原子形成六方密堆积的倾向之间的竞争。预测相的电子和振动性质进行了研究。在二维（2D）半导体中，电子的有效质量小，这对于诸如场效应晶体管的应用是有益的。振动拉曼和红外光谱计算，以方便未来的实验研究。
Layered IV-VI2 compounds often exist in a CdI2 structure. Using the evolution algorithm and first-principles calculations, we predict a novel layered structure of silicon ditelluride (SiTe2) that is more stable than the CdI2 phase. The structure has a triclinic unit cell in its bulk form. The atomic arrangement indicates the competition between the Si atoms' tendency to form tetrahedral bonds and the Te atoms' tendency to form hexagonal close-packing. The electronic and vibrational properties of the predicted phase are investigated. The effective mass of an electron is small among two-dimensional (2D) semiconductors, which is beneficial for applications such as field-effect transistors. The vibrational Raman and IR spectra are calculated to facilitate future experimental investigations.