Temperature-Triggered Sulfur Vacancy Evolution in Monolayer MoS2/Graphene Heterostructures
Temperature-Triggered Sulfur Vacancy Evolution in Monolayer MoS2/Graphene Heterostructures
复制标题
单层MoS2/石墨烯异质结构中温度触发的硫空位演化
DOI：
10.1002/smll.201602967
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发表时间：
2017-10-25
期刊：
影响因子：
13.3
通讯作者：
Liu, Zhongfan
中科院分区：
文献类型：
--
作者：
Liu, Mengxi;Shi, Jianping;Liu, Zhongfan
二维半导体中缺陷的存在被预测会产生独特的物理性质，并显着影响其电子和光电性质。在这项工作中，它被发现，通过化学气相沉积制备的单层MoS2是几乎无缺陷的退火后，在大约400 K的超真空条件下，通过扫描隧道显微镜观察证明。然而，在约900 K的热退火过程后，在Au箔上生长的单层MoS2中存在占主导地位的单硫空位和相对罕见的空位链（2S，3S和4S）。特别重要的是揭示了多功能空位可以调制单层MoS2的能带结构，导致带隙减小和明显的n掺杂效应。这些结果证实了扫描隧道光谱数据以及相关的形态和各种缺陷类型的电子性质的第一性原理理论模拟。简而言之，这项工作应该为缺陷工程铺平了一条新的路线，因此三原子薄的二维层状半导体的电子性质调制。
The existence of defects in 2D semiconductors has been predicted to generate unique physical properties and markedly influence their electronic and optoelectronic properties. In this work, it is found that the monolayer MoS2 prepared by chemical vapor deposition is nearly defect-free after annealing under ultrahigh vacuum conditions at approximate to 400 K, as evidenced by scanning tunneling microscopy observations. However, after thermal annealing process at approximate to 900 K, the existence of dominant single sulfur vacancies and relatively rare vacancy chains (2S, 3S, and 4S) is convinced in monolayer MoS2 as-grown on Au foils. Of particular significance is the revelation that the versatile vacancies can modulate the band structure of the monolayer MoS2, leading to a decrease of the bandgap and an obvious n-doping effect. These results are confirmed by scanning tunneling spectroscopy data as well as first-principles theoretical simulations of the related morphologies and the electronic properties of the various defect types. Briefly, this work should pave a novel route for defect engineering and hence the electronic property modulation of three-atom-thin 2D layered semiconductors.