Vibrational and electronic structures of tin selenide nanowires confined inside carbon nanotubes
Vibrational and electronic structures of tin selenide nanowires confined inside carbon nanotubes
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DOI：
10.1016/j.synthmet.2021.116968
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发表时间：
2022-03-01
期刊：
影响因子：
4.4
通讯作者：
Ivanov, Victor G.
中科院分区：
文献类型：
--
作者：
Faulques, Eric;Kalashnyk, Nataliya;Ivanov, Victor G.
我们在Heyd-Scus eria-Ernzerhof(HSE)水平上结合实验拉曼光谱和密度泛函理论(DFT)计算，研究了单壁碳纳米管(SWCNT)包裹的SnSe纳米线的振动和电子性质。理论上研究的SnSe纳米线是具有方形(2×2)原子排列的Sn4Se4和具有重复的六方Mo6S6结构的Sn6Se6。拉曼数据支持正方形(2×2)纳米线在151 cm(-1)和185 cm(-1)处具有特定模式的理论预测，而六方Sn6Se6结构的特征是在235 cm(-1)附近出现模式。计算表明，(2×2)纳米线的电子能隙为1.5 eV，而Sn6Se6纳米线呈现出半金属特性。SnSe@SWCNT复合样品的拉曼光谱表明，纳米管的径向呼吸模被强烈抑制，表明SWCNT与包裹的SnSe纳米线相互作用，同时G带的Fano不对称参数增加。
We study vibrational and electronic properties of tin selenide (SnSe) nanowires encapsulated in single walled carbon nanotubes (SWCNT) by combining experimental Raman spectroscopy and density functional theory (DFT) calculations at the Heyd-Scuseria-Ernzerhof (HSE) level. The theoretically investigated standalone SnSe nanowires are Sn4Se4 with square (2 x 2) atomic arrangement and Sn6Se6 with a repeating hexagonal Mo6S6-like structure. Raman data support the theoretical prediction that the square (2 x 2) nanowires possess specific modes at 151 and 185 cm(-1), whereas the hexagonal Sn6Se6 structure is characterized by a mode appearing at similar to 235 cm(-1). Calculations predict that the (2 x 2) nanowire has an electronic gap of 1.5 eV and the Sn6Se6 nanowire presents a semi-metallic character. Raman spectra of composite SnSe@SWCNT samples show that the radial breathing mode of the nanotubes is strongly suppressed indicating interaction between SWCNT and the encapsulated SnSe nanowire while the Fano asymmetry parameter of the G band is increased.