Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University , Tainan 701, Taiwan.
Department of Electrical Engineering, University of California at Los Angeles , Los Angeles, California 90095, United States.
ACS Nano. 2017 Nov 28;11(11):11015-11023. doi: 10.1021/acsnano.7b05012. Epub 2017 Oct 24.
High-frequency operation with ultrathin, lightweight, and extremely flexible semiconducting electronics is highly desirable for the development of mobile devices, wearable electronic systems, and defense technologies. In this work, the experimental observation of quasi-heterojunction bipolar transistors utilizing a monolayer of the lateral WSe-MoS junctions as the conducting p-n channel is demonstrated. Both lateral n-p-n and p-n-p heterojunction bipolar transistors are fabricated to exhibit the output characteristics and current gain. A maximum common-emitter current gain of around 3 is obtained in our prototype two-dimensional quasi-heterojunction bipolar transistors. Interestingly, we also observe the negative differential resistance in the electrical characteristics. A potential mechanism is that the negative differential resistance is induced by resonant tunneling phenomenon due to the formation of quantum well under applying high bias voltages. Our results open the door to two-dimensional materials for high-frequency, high-speed, high-density, and flexible electronics.
高频操作需要超薄、超轻、极灵活的半导体电子产品，这对于移动设备、可穿戴电子系统和国防技术的发展是非常理想的。在这项工作中，展示了利用横向 WSe-MoS 结的单层作为导电 p-n 沟道的准异质结双极晶体管的实验观察。制造了横向 n-p-n 和 p-n-p 异质结双极晶体管，以展示输出特性和电流增益。在我们的二维准异质结双极晶体管原型中，获得了约 3 的最大共发射极电流增益。有趣的是，我们还观察到了电特性中的负微分电阻。一种可能的机制是，由于在施加高偏压时形成量子阱，负微分电阻是由共振隧穿现象引起的。我们的结果为二维材料在高频、高速、高密度和柔性电子领域的应用开辟了道路。
