Effect of Intercalated LiF on Interface Contact Characteristics of MoS₂ Field Effect Transistor: A First‐Principles Study

Abstract

Based on the first‐principles calculation, the effect of intercalated LiF on the contact characteristics of the interface between Au electrode and MoS2 layer is studied. It is found that adding LiF film can change the contact type between metal electrode Au and MoS2 layer from Schottky contact to ohmic contact, which is accompanied by interfacial charge transfer from LiF layer to MoS2 layer and the downward movement of d (dxy and dz2) orbital of Mo atom and p (px and py) orbital of S atom to Fermi level. And the interlayer spacing between LiF layer and Au electrode has a great impact on the interface contact characteristics. The electric field effect and stress effect of interface contact of Au, LiF and MoS2 (Au/LiF/MoS2)is more obvious than that of interface contact of Au and MoS2 (Au/MoS2). Au/LiF/MoS2 shows ohmic contact with the interlayer spacing between Au layer and LiF layer less than 3.05 Å and with the electric field less than 0.15 VÅ−1, respectively, while Au/MoS2 still shows N‐type Schottky contact. These findings are helpful to control the contact resistance and have guiding significance for high performance MoS2 field effect transistor and other electronic components.