Electrical Transport Properties of Single-Layer WS2
Electrical Transport Properties of Single-Layer WS2
复制标题
DOI：
10.1021/nn502362b
复制
发表时间：
2014-08-01
期刊：
影响因子：
17.1
通讯作者：
Kis, Andras
中科院分区：
文献类型：
--
作者：
Ovchinnikov, Dmitry;Allain, Adrien;Kis, Andras
我们报道了基于单层和双层半导体WS 2的场效应晶体管的制备及其电子输运性质的研究。我们发现，掺杂水平强烈地依赖于设备的环境和长时间的原位退火大大提高了接触的透明度，允许四端测量进行和原始的材料的属性被恢复。我们的器件显示出n型行为，具有类似于10（6）的高室温开/关电流比。它们在高电荷载流子密度和低温下高达140 cm（2）/（Vs）的迁移率（在双层的情况下高于300 cm（2）/（Vs））下显示出明显的金属行为。在绝缘状态下，器件表现出可变的范围跳跃，随着费米能级进入导带，局域化长度约为2 nm，并开始增加。WS 2具有与单层MoS 2和WSe 2相媲美的良好的电子性质，以及其强的自旋轨道耦合，使其在电子，光学和谷电子器件中的未来应用变得有趣。
We report on the fabrication of field-effect transistors based on single layers and bilayers of the semiconductor WS2 and the investigation of their electronic transport properties. We find that the doping level strongly depends on the device environment and that long in situ annealing drastically improves the contact transparency, allowing four-terminal measurements to be performed and the pristine properties of the material to be recovered. Our devices show n-type behavior with a high room temperature on/off current ratio of similar to 10(6). They show clear metallic behavior at high charge carrier densities and mobilities as high as similar to 140 cm(2)/(V s) at low temperatures (above 300 cm(2)/(V s) in the case of bilayers). In the insulating regime, the devices exhibit variable range hopping, with a localization length of about 2 nm that starts to increase as the Fermi level enters the conduction band. The promising electronic properties of WS2, comparable to those of single layer MoS2 and WSe2, together with its strong spin-orbit coupling, make it interesting for future applications in electronic, optical, and valleytronic devices.