Vertical stacking of different two-dimensional (2D) materials into van der Waals heterostructures exploits the properties of individual materials as well as their interlayer coupling, thereby exhibiting unique electrical and optical properties. Here, we study and investigate a system consisting entirely of different 2D materials for the implementation of electronic devices that are based on quantum mechanical band-to-band tunneling transport such as tunnel diodes and tunnel field-effect transistors. We fabricated and characterized van der Waals heterojunctions based on semiconducting layers of WSe₂ and MoS₂ by employing different gate configurations to analyze the transport properties of the junction. We found that the device dielectric environment is crucial for achieving tunneling transport across the heterojunction by replacing thick oxide dielectrics with thin layers of hexagonal-boronnitride. With the help of additional top gates implemented in different regions of our heterojunction device, it was seen that the tunneling properties as well as the Schottky barriers at the contact interfaces could be tuned efficiently by using layers of graphene as an intermediate contact material.

将不同的二维 (2D) 材料垂直堆叠成范德华异质结构，利用了单个材料的特性及其层间耦合，从而表现出独特的电学和光学特性。在这里，我们研究和研究了一个完全由不同二维材料组成的系统，用于实现基于量子力学带间隧道传输的电子器件，例如隧道二极管和隧道场效应晶体管。我们通过采用不同的栅极配置来分析结的传输特性，制造并表征了基于 WSe ₂和 MoS ₂半导体层的范德华异质结。我们发现，通过用薄层六方氮化硼代替厚氧化物电介质，器件介电环境对于实现跨异质结的隧道传输至关重要。借助在异质结器件的不同区域中实现的额外顶栅，可以发现，通过使用石墨烯层作为中间接触材料，可以有效地调节接触界面处的隧道特性以及肖特基势垒。