Controlling of the electronic properties of WS2 and graphene oxide heterostructures from first-principles calculations
Controlling of the electronic properties of WS2 and graphene oxide heterostructures from first-principles calculations
复制标题
通过第一性原理计算控制 WS2 和氧化石墨烯异质结构的电子特性
DOI：
10.1039/c6tc04487e
复制
发表时间：
2017-01-07
影响因子：
6.4
通讯作者：
Li, Youyong
中科院分区：
文献类型：
--
作者：
Yang, Mingye;Wang, Lu;Li, Youyong
二维纳米材料引起了广泛关注，其异质结构具有优异的电子和光学性质，适用于多种应用。基于第一性原理计算，我们研究了二硫化钨（WS₂）和氧化石墨烯（GO）异质结构的结构稳定性和电子性质。我们考虑了三种类型的氧化石墨烯，包括仅含环氧基、仅含羟基以及氧化石墨烯表面同时含有环氧基和羟基的情况。我们的结果表明，随着氧化石墨烯表面氧浓度的增加，每个WS₂单元的层间结合能从0.117电子伏特增加到0.214电子伏特。通过改变氧官能团和浓度，WS₂/GO异质结构的带隙可以在0.13电子伏特到1.91电子伏特的宽范围内有效调节。观察到导带底和价带顶在空间上分离，且分布在不同层。此外，WS₂的功函数也可被氧化石墨烯在4.09电子伏特到6.34电子伏特的范围内调节，这有可能增加载流子浓度，并拓宽WS₂和其他过渡金属二硫化物材料在光电器件中的应用。
Two-dimensional nanomaterials have attracted extensive interest and their heterostructures possess excellent electronic and optical properties suitable for various applications. Based on first-principles calculations, we investigated the structural stability and electronic properties of WS2 and graphene oxide (GO) heterostructures. We considered three types of GO, including epoxy only, hydroxyl only and both epoxy and hydroxyl on the GO surface. Our results show that the interlayer binding energy per WS2 unit increases from 0.117 eV to 0.214 eV as the surface oxygen concentration of GO increases. The band gap of the WS2/GO heterostructures can be efficiently tuned in a wide range from 0.13 eV to 1.91 eV by changing the oxygen functionalities and the concentration. The spatial separation of the conduction band minimum and valence band maximum is observed, which are distributed in different layers. In addition, the work function of WS2 can also be modulated by GO in the range of 4.09 eV to 6.34 eV, which potentially increases the carrier concentration and broadens the applications of WS2 and other transition metal dichalcogenide materials in optoelectronic devices.