Schottky contacts in graphene and few layers Janus MoSSe van der Waals heterostructure

In this study, we made the graphene contact with monolayer MoSSe in two ways as G/SMoSe and G/SeMoS after which the electronic properties, Schottky contact, and barrier height were obtained for both contact sides. An n-type Schottky contact was observed for both structures with reasonable SBH. To further investigate the contact type and barrier height as a function of layer thickness, bilayers of the Janus MoSSe were vertically stacked on graphene as G/SeMoS-SMoSe, G/SMoSe-SeMoS, G/SeMoS-SeMoS and G/SMoSe-SMoSe (G/Se-S-S-Se, G/S-Se-Se-S, G/Se-S-Se-S and G/S-Se-S-Se). The band behaviours for the various structures were studied with varying band gap opening in the graphene Dirac point of the heterostructures. A p-type contact was attained in G/Se-S-Se-S and G/Se-S-S-Se while an n-type contact attained for the other two. Barrier heights of 0.41, 0.42, 0.19 and 0.02 eV were calculated which further investigation confirms their tunability. It was also noticed that charges were transferred between the graphene and Janus MoSSe layers (graphene accepting in some and donating in others). Unlike the monolayer MoSSe/graphene, we observed Schottky to Ohmic transition in the G/S-Se-S-Se when strained.

Automated summary

In this study, graphene was contacted with monolayer MoSSe in two ways, resulting in n-type and p-type Schottky contacts. The type of contact and barrier height were found to be influenced by layer thickness, with tunable barrier heights observed. Strain-induced Schottky to Ohmic transitions were observed in the study.