Modulating the electronic properties of monolayer MoS2 through heterostructure with monolayer gray arsenic

Two-dimensional layered materials attract much attention due to their outstanding intrinsic properties and wide applications. In this work, the mechanical and electronic properties of monolayer MoS2 on monolayer gray arsenic (g-As) substrates are studied by first-principles calculations. Results indicate that both g-As and MoS2 undergo small corrugations when monolayer MoS2 is bonded to g-As. The lowest binding energies (similar to-0.05 eV) and the electronic structures are almost independent of the atomic arrangement. But the indirect band gap of g-As/MoS2 heterostructure enlarges with increasing the interlayer distance. Moreover, the valence band maximum consists of pi-like states rather than sigma states upon the formation of g-As/MoS2 heterostructures. Interestingly, complete electron-hole separation is found in the g-As/MoS2 heterostructures, which can facilitate the application of MoS2 on photoelectric device. In addition, the work function of monolayer MoS2 shifts down upon the g-As/MoS2 heterostructures formation since a certain charge transfer is found between MoS2 and g-As even though the interlayer interaction is very weak. Our findings provide a detailed understanding of the nature physical properties of g-As/MoS2 heterostructures, and suggest a simple way to fabricate and improve the application of monolayer MoS2 in nanodevices. (C) 2016 Elsevier Ltd. All rights reserved.