MoS2-graphene heterostructures as efficient organic compounds sensing 2D materials
MoS2-graphene heterostructures as efficient organic compounds sensing 2D materials
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DOI：
10.1016/j.carbon.2018.10.079
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发表时间：
2019-02-01
期刊：
影响因子：
10.9
通讯作者：
Mulchandani, Ashok
中科院分区：
文献类型：
--
作者：
Pham, Tung;Ramnani, Pankaj;Mulchandani, Ashok
本文研究了二硫化钼(MoS_2)-石墨烯(MS/G)异质结的电学性质及其在挥发性有机物检测中的应用。利用单层MoS_2在单层石墨烯上的物理堆积合成了MS/G异质结构。MoS_2和石墨烯之间功函数的不同导致了电子从MoS_2到石墨烯的转移，从而使石墨烯的场效应场效应电荷中性点(V-CNP)提高了30V，从而增加了石墨烯中的电子空穴比。异质结中MoS_2的拉曼G峰位移和光致发光强度猝灭进一步证实了这种电荷输运现象。紫外光电子能谱显示，在MS/G中，石墨烯的费米能级上移了0.1 eV，这与双电层电容与第一性原理模拟预测的电极电势测量和能带排列相一致。MS/G异质结中的异质诱导电荷转移使其在化学传感方面表现出优异的性能。与石墨烯FET相比，MS/G FET在干燥空气中表现出更好的稳定性，而V-CNP的漂移可以忽略不计。在甲苯的检测中，基于MS/G FET的传感器与MoS2或石墨烯相比，具有更高的灵敏度和更高的信噪比。(C)爱思唯尔有限公司出版。
In this work, electrical properties and application for volatile organic compounds detection of molybdenum disulfide (MoS2)-graphene (MS/G) heterostructure is investigated. The MS/G heterostructure is synthesized by physical stacking of single-layer (SL) MoS2 over SL graphene. The difference in the work-functions between the MoS2 and graphene leads to electron transfer from MoS2 to graphene, which changes FET charge neutrality point (V-CNP) of graphene by as much as 30 V and increases the electron-to-hole ratio in graphene. This charge transport phenomenon is further confirmed by shifting of Raman G peak and quenching of photoluminescence intensity by 50% of MoS2 in the heterostructure. Ultraviolet photoelectron spectroscopy reveals a 0.1 eV upshift of the Fermi level of graphene in MS/G, which is consistent with the electrical double-layer capacitance versus the electrode potential measurement and energy band alignment predicted by first-principle simulations. The heterogenity induced charge transfer in the heterostructure of MS/G results in outstanding performance in chemical sensing. The MS/G FET shows improved stability in dry air with negligible shifting of V-CNP, as compared to graphene FET. In the detection of toluene, the MS/G FET-based sensor shows higher sensitivity and superior signal-to-noise ratio compared to MoS2 or graphene individually. (C) Published by Elsevier Ltd.