Institute of Physics, Academia Sinica , Taipei 11529, Taiwan.
Nano Lett. 2014 May 14;14(5):2381-6. doi: 10.1021/nl404790n. Epub 2014 Apr 22.
Two-dimensional crystals can be assembled into three-dimensional stacks with atomic layer precision, which have already shown plenty of fascinating physical phenomena and been used for prototype vertical-field-effect-transistors.1,2 In this work, interlayer electron tunneling in stacked high-quality crystalline MoS2 films were investigated. A trilayered MoS2 film was sandwiched between top and bottom electrodes with an adjacent bottom gate, and the discrete energy levels in each layer could be tuned by bias and gate voltages. When the discrete energy levels aligned, a resonant tunneling peak appeared in the current-voltage characteristics. The peak position shifts linearly with perpendicular magnetic field, indicating formation of Landau levels. From this linear dependence, the effective mass and Fermi velocity are determined and are confirmed by electronic structure calculations. These fundamental parameters are useful for exploitation of its unique properties.
二维晶体可以通过原子层精度组装成三维堆叠，这些堆叠已经展示出了许多迷人的物理现象，并被用于原型垂直场效应晶体管。1,2 在这项工作中，我们研究了堆叠高质量结晶 MoS2 薄膜中的层间电子隧穿。三层 MoS2 薄膜被夹在顶部和底部电极之间，并用相邻的底部栅极隔开，每个层中的离散能级可以通过偏压和栅极电压进行调节。当离散能级对齐时，电流-电压特性中会出现共振隧穿峰。峰的位置随垂直磁场线性移动，表明形成了 Landau 能级。从这个线性关系中，可以确定有效质量和费米速度，并通过电子结构计算得到验证。这些基本参数对于开发其独特性质是有用的。
