Hysteresis-Free Hexagonal Boron Nitride Encapsulated 2D Semiconductor Transistors, NMOS and CMOS Inverters

Graphene and subsequently discovered layered semiconducting transition metal dichalcogenides (TMDCs) exhibit numerous exotic physical properties and broad potential device applications. These 2D semiconducting TMDCs have become particularly interesting in next-generation electronic device applications due to their atomic thickness and nonzero bandgap. However, as there is no bulk volume, the 2D nature makes the electronic transport in these crystals highly sensitive to the environmental conditions, such as humidity, adsorbates, and trapped charges in neighboring dielectrics. Due to this environmental sensitivity, 2D-based circuits and devices suffer from a large and undesirable environment-induced hysteresis, which must be eliminated for reliable operation and computation. By mechanically assembling van der Waals (vdWs) heterostructures and edge-contacted graphite electrodes, the 2D semiconducting channel is sealed completely and protected. Here, hexagonal boron nitride (hBN) encapsulated high-performance, hysteresis-free 2D semiconductor transistors, n-type metal-oxide semiconductor, and complementary metal-oxide semiconductor inverters are fabricated. The hBN encapsulation provides excellent protection of semiconducting n-MoS₂ and p-WSe₂ from environmental factors, resulting in hysteresis-free 2D electronics characteristics that are necessary for the realization of 2D electronics and computing.