Metal-insulator transition in variably doped (Bi1-xSbx)(2)Se-3 nanosheets

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	Metal-insulator transition in variably doped (Bi1-xSbx)(2)Se-3 nanosheets
	C. H. Lee; R. He; Z. H. Wang; R. L. J. Qiu; A. Kumar; C. Delaney; B. Beck; T. E. Kidd; C. C. Chancey; R. M. Sankaran; X. P. A. Gao
	2013
发表期刊	Nanoscale
ISSN	2040-3364
卷号	5 期号:10 页码:4337-4343
摘要	Topological insulators are novel quantum materials with metallic surface transport but insulating bulk behavior. Often, topological insulators are dominated by bulk contributions due to defect induced bulk carriers, making it difficult to isolate the more interesting surface transport characteristics. Here, we report the synthesis and characterization of nanosheets of a topological insulator Bi2Se3 with variable Sb-doping levels to control the electron carrier density and surface transport behavior. (Bi1-xSbx)(2)Se-3 thin films of thickness less than 10 nm are prepared by epitaxial growth on mica substrates in a vapor transport setup. The introduction of Sb in Bi2Se3 effectively suppresses the room temperature electron density from similar to 4 x 10(13) cm(-2) in pure Bi2Se3 (x = 0) to similar to 2 x 10(12) cm(-2) in (Bi1-xSbx)(2)Se-3 at x similar to 0.15, while maintaining the metallic transport behavior. At x greater than or similar to similar to 0.20, a metal-insulator transition (MIT) is observed, indicating that the system has transformed into an insulator in which the metallic surface conduction is blocked. In agreement with the observed MIT, Raman spectroscopy reveals the emergence of vibrational modes arising from Sb-Sb and Sb-Se bonds at high Sb concentrations, confirming the appearance of the Sb2Se3 crystal structure in the sample. These results suggest that nanostructured chalcogenide films with controlled doping can be a tunable platform for fundamental studies and electronic applications of topological insulator systems.
部门归属	[lee, chee huei ; wang, zhenhua ; qiu, richard l. j. ; gao, xuan p. a.] case western reserve univ, dept phys, cleveland, oh 44106 usa. [lee, chee huei ; kumar, ajay ; sankaran, r. mohan] case western reserve univ, dept chem engn, cleveland, oh 44106 usa. [he, rui ; delaney, conor ; beck, ben ; kidd, t. e. ; chancey, c. c.] univ no iowa, dept phys, cedar falls, ia 50614 usa. [wang, zhenhua] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [wang, zhenhua] chinese acad sci, int ctr mat phys, shenyang 110016, peoples r china. ; he, r (reprint author), univ no iowa, dept phys, cedar falls, ia 50614 usa. ; rui.he@uni.edu ; xuan.gao@case.edu
关键词	Tunable Topological Insulator Single Dirac Cone Phase-transition Surface-states Bi2se3 Bi2te3 Nanoribbons Sb2te3 Realization Conduction
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语种	英语
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/71300
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	C. H. Lee,R. He,Z. H. Wang,et al. Metal-insulator transition in variably doped (Bi1-xSbx)(2)Se-3 nanosheets[J]. Nanoscale,2013,5(10):4337-4343.
APA	C. H. Lee.,R. He.,Z. H. Wang.,R. L. J. Qiu.,A. Kumar.,...&X. P. A. Gao.(2013).Metal-insulator transition in variably doped (Bi1-xSbx)(2)Se-3 nanosheets.Nanoscale,5(10),4337-4343.
MLA	C. H. Lee,et al."Metal-insulator transition in variably doped (Bi1-xSbx)(2)Se-3 nanosheets".Nanoscale 5.10(2013):4337-4343.