Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
Nano Lett. 2016 Jul 13;16(7):4297-304. doi: 10.1021/acs.nanolett.6b01342. Epub 2016 Jun 20.
Growth of transition metal dichalcogenide (TMD) monolayers is of interest due to their unique electrical and optical properties. Films in the 2H and 1T phases have been widely studied but monolayers of some 1T'-TMDs are predicted to be large-gap quantum spin Hall insulators, suitable for innovative transistor structures that can be switched via a topological phase transition rather than conventional carrier depletion [ Qian et al. Science 2014 , 346 , 1344 - 1347 ]. Here we detail a reproducible method for chemical vapor deposition of monolayer, single-crystal flakes of 1T'-MoTe2. Atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy confirm the composition and structure of MoTe2 flakes. Variable temperature magnetotransport shows weak antilocalization at low temperatures, an effect seen in topological insulators and evidence of strong spin-orbit coupling. Our approach provides a pathway to systematic investigation of monolayer, single-crystal 1T'-MoTe2 and implementation in next-generation nanoelectronic devices.
过渡金属二卤化物 (TMD) 单层的生长因其独特的电学和光学性质而备受关注。2H 和 1T 相的薄膜已经得到了广泛的研究,但一些 1T'-TMD 的单层被预测为大带隙量子自旋霍尔绝缘体,适合用于通过拓扑相变而不是传统的载流子耗尽来切换的创新晶体管结构[Qian 等人,科学 2014,346,1344-1347]。在这里,我们详细介绍了一种用于化学气相沉积单层单晶 MoTe2 薄片的可重复方法。原子力显微镜、拉曼光谱、X 射线光电子能谱和透射电子显微镜证实了 MoTe2 薄片的组成和结构。变温磁输运在低温下表现出弱反局域,这一效应在拓扑绝缘体中可见,是强自旋轨道耦合的证据。我们的方法为系统研究单层单晶 1T'-MoTe2 并将其应用于下一代纳米电子器件提供了途径。