Direct Measurement of the Tunable Electronic Structure of Bilayer MoS2 by Interlayer Twist.
Direct Measurement of the Tunable Electronic Structure of Bilayer MoS2 by Interlayer Twist.
复制标题
DOI：
10.1021/acs.nanolett.5b03883
复制
发表时间：
2016-01
期刊：
影响因子：
10.8
通讯作者：
P. Yeh;Wencan Jin;N. Zaki;J. Kunstmann;Daniel A. Chenet;Ghidewon Arefe;J. Sadowski;J. Dadap;P. Sutter;J. Hone;R. Osgood
中科院分区：
文献类型：
--
作者：
P. Yeh;Wencan Jin;N. Zaki;J. Kunstmann;Daniel A. Chenet;Ghidewon Arefe;J. Sadowski;J. Dadap;P. Sutter;J. Hone;R. Osgood
利用角度分辨光电发射技术，在微米尺度的样品区域上，我们直接测量了双层二硫化钼（MoS 2）的层间扭曲角依赖的电子能带结构。我们的测量，在任意堆叠的双层MoS 2薄片通过化学气相沉积制备，提供了直接的证据的准粒子的能量的价带在布里渊区中心（Γ-点）与层间扭转角，高达120 meV的最大值在扭转角为120 °。我们的价带结构的直接测量，使提取的空穴有效质量作为层间扭曲角的函数。虽然我们的结果与最近发表的光致发光数据一致，但我们对整个2D布里渊区的准粒子光谱的测量揭示了电子结构比以前理论预测的更丰富和更复杂的变化。电子结构的测量报告，包括有效质量与扭转角的演变，提供了新的洞察到扭曲的过渡金属双硫族化合物双层的物理和作为指导的二硫化钼光电和自旋/谷电子器件的实际设计。
Using angle-resolved photoemission on micrometer-scale sample areas, we directly measure the interlayer twist angle-dependent electronic band structure of bilayer molybdenum-disulfide (MoS2). Our measurements, performed on arbitrarily stacked bilayer MoS2 flakes prepared by chemical vapor deposition, provide direct evidence for a downshift of the quasiparticle energy of the valence band at the Brillouin zone center (Γ̅ point) with the interlayer twist angle, up to a maximum of 120 meV at a twist angle of ∼40°. Our direct measurements of the valence band structure enable the extraction of the hole effective mass as a function of the interlayer twist angle. While our results at Γ̅ agree with recently published photoluminescence data, our measurements of the quasiparticle spectrum over the full 2D Brillouin zone reveal a richer and more complicated change in the electronic structure than previously theoretically predicted. The electronic structure measurements reported here, including the evolution of the effective mass with twist-angle, provide new insight into the physics of twisted transition-metal dichalcogenide bilayers and serve as a guide for the practical design of MoS2 optoelectronic and spin-/valley-tronic devices.