Electronic band structure of single-crystal and single-layer WS2:: Influence of interlayer van der Waals interactions -: art. no. 205416
Electronic band structure of single-crystal and single-layer WS2:: Influence of interlayer van der Waals interactions -: art. no. 205416
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DOI：
10.1103/physrevb.64.205416
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发表时间：
2001-11-15
影响因子：
3.7
通讯作者：
Jaegermann, W
中科院分区：
文献类型：
--
作者：
Klein, A;Tiefenbacher, S;Jaegermann, W
通过角分辨光电子能谱和基于密度泛函理论的增广球面波能带结构计算，对层状过渡金属二硫属化物WS2的价带结构进行了实验研究.实验和计算的能带结构之间的良好协议观察到单晶WS2。用金属有机货车德瓦尔斯外延法在单晶石墨衬底上制备了一种电子去耦膜，并测定了该膜的能带结构。单层膜的偏振相关光电发射选择规则适用于自支撑膜。实验单层能带结构显示出一些差异相比，带结构计算使用层内的散装原子位置。我们的结论是，松弛的单层发生作为一个结果，导致单层和单晶的电子结构之间的密切协议的缺失层间相互作用。由于缺少层间相互作用，单层的价带最大值位于布里渊区的K点处。
The valence band structure of the layered transition metal dichalcogenide WS2 has been determined experimentally by angle resolved photoelectron spectroscopy and theoretically by augmented spherical wave band structure calculations as based on density functional theory. Good agreement between experimental and calculated band structure is observed for single crystal WS2. An experimental band structure of a single layer was determined from an electronically decoupled film prepared on a single crystalline graphite substrate by metalorganic van der Waals epitaxy. The polarization dependent photoemission selection rules of the single layer film are appropriate for a free standing film. The experimental single layer band structure shows some differences compared to band structure calculations using bulk atomic positions within the layer. We conclude that relaxation of the single layer occurs as a consequence of the missing interlayer interactions leading to close agreement between electronic structure of the single layer and single crystal. As a consequence of the missing interlayer interactions the valence band maximum for the single layer is located at the K point of the Brillouin zone.