journal article·2018-02-01Open access

Electronic structure of monolayer 1T′-MoTe2 grown by molecular beam epitaxy

Shujie Tang, Chaofan Zhang, Chunjing Jia, Hyejin Ryu, Choongyu Hwang, Makoto Hashimoto, Donghui Lu, Zhi Liu, Thomas P. Devereaux, Zhi-Xun Shen, Sung-Kwan Mo

APL Materials· Volume 6· Issue 2

Abstract

Monolayer transition metal dichalcogenides (TMDCs) in the 1T′ structural phase have drawn a great deal of attention due to the prediction of quantum spin Hall insulator states. The band inversion and the concomitant changes in the band topology induced by the structural distortion from 1T to 1T′ phases are well established. However, the bandgap opening due to the strong spin-orbit coupling (SOC) is only verified for 1T′-WTe2 recently and still debated for other TMDCs. Here we report a successful growth of high-quality monolayer 1T′-MoTe2 on a bilayer graphene substrate through molecular beam epitaxy. Using in situ angle-resolved photoemission spectroscopy (ARPES), we have investigated the low-energy electronic structure and Fermi surface topology. The SOC-induced breaking of the band degeneracy points between the valence and conduction bands is clearly observed by ARPES. However, the strength of SOC is found to be insufficient to open a bandgap, which makes monolayer 1T′-MoTe2 on bilayer graphene a semimetal.
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Research context

OpenAlex topics: 2D Materials and Applications · Graphene research and applications · Topological Materials and Phenomena

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory 1 , 2575 Sand Hill Road, Menlo Park, California 94025, USA

Geballe Laboratory for Advanced Materials, Departments of Physics and Applied Physics, Stanford University 2 , Stanford, California 94305, USA

Advanced Light Source, Lawrence Berkeley National Laboratory 3 , Berkeley, California 94720, USA

State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences 4 , Shanghai 200050, China

School of Physical Science and Technology, Shanghai Tech University 5 , Shanghai 200031, China

College of Optoelectronic Science and Engineering, National University of Defense Technology 6 , Changsha 410073, China

Interdisciplinary Center of Quantum Information, National University of Defense Technology 7 , Changsha 410073, China

Max Planck-POSTECH/Hsinchu Center for Complex Phase Materials, Max Plank POSTECH/Korea Research Initiative (MPK) 8 , Gyeongbuk 37673, South Korea

Department of Physics, Pusan National University 9 , Busan 46241, South Korea

Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory 10 , 2575 Sand Hill Road, Menlo Park, California 94025, USA

Funding

National Natural Science Foundation of China · National Research Foundation of Korea · U.S. Department of Energy · National Research Foundation · DOE | LDRD | Lawrence Berkeley National Laboratory

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