Modulation of the transport properties of metal/MoS₂ interfaces using BN-graphene lateral tunneling layers

Abstract

Modulating the n- and p-type interfacial charge transport properties of the metal–semiconductor interface is vital to realizing high performance two-dimensional material nanodevices and is still a significant challenge. Here, a boron nitride (BN)-graphene lateral heterostructure (LH) was used as the interfacial tunneling layer to control the Schottky barrier, Fermi level pinning and charge injection efficiency of the metal–MoS2 interface. The BN-graphene LH with graphene-N junction structure decreased the n-type vertical Schottky barrier and enhanced the interfacial tunneling probability, while the graphene-B junction structure decreased the p-type vertical Schottky barrier. Consequently, the n-type Au/LH–MoS2 interface with Ohmic character and high tunneling probability (∼0.242) and the p-type vertical Schottky barrier of about 0.20 eV for the Pt/LH–MoS2 interface were achieved. Compared to other reported BN or graphene tunneling layers, such a BN-graphene LH tunneling layer not only suppressed the charge scattering from the metal electrode to the MoS2 layer and the Fermi level pinning effect, but also reduced the contact resistance between metal electrode and tunneling layer. The underlying mechanisms were revealed to be due to the charge transfer, orbitals and interfacial dipole. This work improves the current understanding of the metal–MoS2 interface and proposes a new way to overcome the current severe contact issues for future nanoelectronic and optoelectronic applications.

Bi2Se3/Bi2Se3 and TlSe/TlSe junctions: enhanced coupling of topological interface states by intercalation

“…Intercalation at the interface may change the coupling of the interface states. It may be interesting to study the influence of hexagonal BN on the coupling, since hexagonal BN is a well-known 2D substrate and insulator [45][46][47]. Note that the topological band gap in TlSe is much larger than that in Bi 2 Se 3 [22,48] and the coupling of the interface states is relatively insensitive to the interface spacing.…”