Van der Waals bipolar junction transistors based on vertically stacked 2D materials (V2D‐BJT) are proposed, and experimental studies are conducted on the V2D‐BJT using an MoS2/WSe2/MoS2 heterostructure in an n‐p‐n configuration. The V2D‐BJT shows excellent gas sensing performance with a low power dissipation (≈2 nW), a fast response (9 s), and a fast recovery (35 s) time. Abstract The majority of microelectronic devices rely on a p‐n junction. The process of making such a junction is complicated, and it is difficult to make layers that form a junction with an atomic thickness. In this study, bipolar junctions are made by using 2D atomic crystalline layers and even a single layer in which 2D layers adhere together to form a heterostructure via van der Waals forces. A vertical 2D bipolar junction transistor (V2D‐BJT) is studied for the first time. It uses an MoS2/WSe2/MoS2 heterostructure and has an n‐p‐n configuration that exhibits a maximum common‐base current gain of ≈0.97 and a stable common‐emitter current gain (β) of 12 with a nanowatt power consumption. In the first attempt at gas sensing, it shows outstanding performance, exhibiting a very fast response and recovery time (9 and 35 s, respectively) with a power dissipation of only 2 nW. This study demonstrates the potential application of the V2D‐BJT in nanowatt power amplifiers as well as fast‐response and low‐power gas sensors.

Published in: "Advanced Functional Materials".