Direct Measurement of the Electronic Structure and band gap nature of atomic-layer-thick 2H-MoTe2

Wenjuan Zhao; Xieyu Zhou; Dayu Yan; Yuan Huang; Cong Li; Qiang Gao; Hongtao Rong; Yongqing Cai; Eike F. Schwier; Dianxing Ju; Cheng Shen; Yang Wang; Yu Xu; Wei Ji; Youguo Shi; Lin Zhao; Lihong Bao; Qingyan Wang; Kenya Shimada; Xutang Tao; Hongjun Gao; Zuyan Xu; Xingjiang Zhou; Guodong Liu

arXiv · 2001.05894

Direct Measurement of the Electronic Structure and band gap nature of atomic-layer-thick 2H-MoTe2

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Abstract

The millimeter sized monolayer and bilayer 2H-MoTe2 single crystal samples are prepared by a new mechanical exfoliation method. Based on such high-quality samples, we report the first direct electronic structure study on them, using standard high resolution angle-resolved photoemission spectroscopy (ARPES). A direct band gap of 0.924eV is found at K in the rubidium-doped monolayer MoTe2. Similar valence band alignment is also observed in bilayer MoTe2,supporting an assumption of a analogous direct gap semiconductor on it. Our measurements indicate a rather large band splitting of 212meV at the valence band maximum (VBM) in monolayer MoTe2, and the splitting is systematically enlarged with layer stacking, from monolayer to bilayer and to bulk. Meanwhile, our PBE band calculation on these materials show excellent agreement with ARPES results. Some fundamental electronic parameters are derived from the experimental and calculated electronic structures. Our findings lay a foundation for further application-related study on monolayer and bilayer MoTe2.

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Wenjuan Zhao, Xieyu Zhou, Dayu Yan, Yuan Huang, Cong Li, Qiang Gao, Hongtao Rong, Yongqing Cai, Eike F. Schwier, Dianxing Ju, Cheng Shen, Yang Wang, Yu Xu, Wei Ji, Youguo Shi, Lin Zhao, Lihong Bao, Qingyan Wang, Kenya Shimada, Xutang Tao, Hongjun Gao, Zuyan Xu, Xingjiang Zhou, Guodong Liu. 2020-01-16. Direct Measurement of the Electronic Structure and band gap nature of atomic-layer-thick 2H-MoTe2. https://arxiv.org/abs/2001.05894

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