State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, 200433, China.
State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai, 200433, China.
Small. 2017 May;13(18). doi: 10.1002/smll.201604319. Epub 2017 Mar 10.
The abundant electronic and optical properties of 2D materials that are just one-atom thick pave the way for many novel electronic applications. One important application is to explore the band-to-band tunneling in the heterojunction built by different 2D materials. Here, a gate-controlled WSe transistor is constructed by using different work function metals to form the drain (Pt) and source (Cr) electrodes. The device can be gate-modulated to exhibit three modes of operation, i.e., the tunneling mode with remarkable negative differential resistance, the transition mode with a second electron tunneling phenomenon for backward bias, and finally the conventional diode mode with rectifying characteristics. In contrast to the heterojunctions built by different 2D materials, these devices show significantly enhanced tunneling current by two orders of magnitude, which may largely benefit from the clean interfaces. These results pave the way toward design of novel electronic devices using the modulation of metal work functions.
二维材料的丰富电子和光学性质，厚度仅为一个原子层，为许多新型电子应用铺平了道路。其中一个重要的应用是探索由不同二维材料构建的异质结中的带间隧穿。在这里，通过使用不同功函数的金属来构建栅控 WSe 晶体管，形成漏极（Pt）和源极（Cr）电极。该器件可以通过栅极进行调制，以表现出三种工作模式，即具有显著负微分电阻的隧穿模式、反向偏置时出现第二个电子隧穿现象的过渡模式，以及最终具有整流特性的常规二极管模式。与由不同二维材料构建的异质结相比，这些器件的隧穿电流显著增强了两个数量级，这可能主要得益于其清洁的界面。这些结果为利用金属功函数的调制来设计新型电子器件铺平了道路。
