论文标题
直接测量电子结构和原子厚度2H-mote2的带隙性质
Direct Measurement of the Electronic Structure and band gap nature of atomic-layer-thick 2H-MoTe2
论文作者
论文摘要
毫米大小的单层和双层2H-MOTE2单晶样品是通过一种新的机械剥落方法制备的。基于这样的高质量样品，我们使用标准高分辨率分辨光发射光谱（ARPES）报告了对它们的首次直接电子结构研究。在Rubidium掺杂的单层Mote2中，在K中发现了一个直接带隙为0.924EV。在双层Mote2中也观察到类似的价谱带比对，这支持了上面上类似的直接间隙半导体的假设。我们的测量结果表明，在单层Mote2中，在价频带最大值（VBM）处的212mev的频带分裂相当大，并且分裂被系统地扩大，并从单层到双层和散装。同时，我们对这些材料的PBE频带计算与ARPES结果非常吻合。一些基本电子参数来自实验和计算的电子结构。我们的发现为单层和双层MOTE2进行进一步的应用相关研究奠定了基础。
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.
