Interlayer vibrational modes in few-quintuple-layer Bi2Te3 and Bi2Se3   two-dimensional crystals: Raman spectroscopy and first-principles   studies

doi:10.1103/PhysRevB.90.245428

CORC > 北京大学 > 化学与分子工程学院

	Interlayer vibrational modes in few-quintuple-layer Bi2Te3 and Bi2Se3 two-dimensional crystals: Raman spectroscopy and first-principles studies
	Zhao, Yanyuan ; Luo, Xin ; Zhang, Jun ; Wu, Junxiong ; Bai, Xuxu ; Wang, Meixiao ; Jia, Jinfeng ; Peng, Hailin ; Liu, Zhongfan ; Quek, Su Ying ; Xiong, Qihua
刊名	physical review b
	2014
关键词	ENHANCED THERMOELECTRIC PROPERTIES TOPOLOGICAL INSULATOR NANORIBBONS NANOPLATELET COMPOSITES LATTICE-VIBRATIONS GRAPHENE SURFACE SB2TE3
DOI	10.1103/PhysRevB.90.245428
英文摘要	Layered materials, such as graphite/graphene, boron nitride, transition metal dichalcogenides, represent materials in which reduced size, dimensionality, and symmetry play critical roles in their physical properties. Here, we report on a comprehensive investigation of the phonon properties in the topological insulator Bi2Te3 and Bi2Se3 two-dimensional (2D) crystals, with the combination of Raman spectroscopy, first-principles calculations, and group theory analysis. Low frequency (<30 cm (1)) interlayer vibrational modes are revealed in few-quintuple-layer (QL) Bi2Te3/Bi2Se3 2D crystals, which are absent in the bulk crystal as a result of different symmetries. The experimentally observed interlayer shear and breathing mode frequencies both show blueshifts, with decreasing thickness in few-QL Bi2Te3 (down to 2QL) and Bi2Se3 (down to 1QL), in agreement with first-principles calculations and a linear chain model, from which the interlayer coupling force constants can be estimated. Besides, an intense ultralow (<12 cm(-1)) frequency peak is observed in 2-4QL Bi2Te3, which is tentatively attributed to a substrate-induced interface mode supported by a linear chain model analysis. The high frequency Raman peaks exhibit frequency shifts and broadening from 3D to 2D as a result of the phonon confinement effect. Our studies shed light on a general understanding of the influence of dimensionality and crystal symmetry on the phonon properties in layered materials.; Physics, Condensed Matter; SCI(E); 0; ARTICLE; queksy@ihpc.a-star.edu.sg; Qihua@ntu.edu.sg; 24; 90
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/387764]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Zhao, Yanyuan,Luo, Xin,Zhang, Jun,et al. Interlayer vibrational modes in few-quintuple-layer Bi2Te3 and Bi2Se3 two-dimensional crystals: Raman spectroscopy and first-principles studies[J]. physical review b,2014.
APA	Zhao, Yanyuan.,Luo, Xin.,Zhang, Jun.,Wu, Junxiong.,Bai, Xuxu.,...&Xiong, Qihua.(2014).Interlayer vibrational modes in few-quintuple-layer Bi2Te3 and Bi2Se3 two-dimensional crystals: Raman spectroscopy and first-principles studies.physical review b.
MLA	Zhao, Yanyuan,et al."Interlayer vibrational modes in few-quintuple-layer Bi2Te3 and Bi2Se3 two-dimensional crystals: Raman spectroscopy and first-principles studies".physical review b (2014).