Schottky barrier heights and band alignments in transition metal dichalcogenides
Schottky barrier heights and band alignments in transition metal dichalcogenides
复制标题
DOI：
10.1016/j.mee.2015.04.069
复制
发表时间：
2015-11-01
影响因子：
2.3
通讯作者：
Robertson, John
中科院分区：
文献类型：
--
作者：
Guo, Yuzheng;Robertson, John
MoS2 等层状过渡金属二硫属化物 (TMD) 上金属的肖特基势垒高度 (SBH) 通过密度泛函理论使用超晶胞模型进行计算。尽管层之间存在范德华键合，但发现金属与顶部接触结构中的硫族元素位点相当牢固地键合，而不会干扰层内共价键合。这使得 SBH 能够遵循适用于常规 3D 半导体的金属诱导间隙态 (MIGS) 模型，并给出类似于 0.3 的钉扎因子 S。额外的钉扎是由硫族化物位点空位引起的。人们发现 MoS2 有利于 n 型器件，因为钉扎能级位于其上部间隙中。其他化合物如 MoSe2、WS2 或 WSe2 在中间能隙附近具有钉扎能级，从而允许双极性行为。 (C) 2015 Elsevier B.V. 保留所有权利。
The Schottky barrier heights (SBHs) of metals on the layered transition metal dichalcogenides (TMDs) like MoS2 are calculated by density functional theory using supercell models. Despite the presence of van der Waals bonding between the layers, the metals are found to bond quite strongly to the chalcogen sites in the top contact configuration, without disturbing the intralayer covalent bonding. This allows the SBHs to follow the metal induced gap state (MIGS) model that applies to regular 3D semiconductors, and gives a pinning factor S similar to 0.3. Additional pinning is caused by chalcogenide site vacancies. MoS2 is found to favor n-type devices, because the pinning levels are in its upper gap. Other compounds like MoSe2, WS2 or WSe2 have pinning levels around midgap, allowing ambipolar behavior. (C) 2015 Elsevier B.V. All rights reserved.