Interfacial properties of monolayer PtSe2 FETs: A comparative study of traditional metal and semimetal electrodes

In this work, the interfacial properties of field-effect transistors (FETs) based on monolayer PtSe₂ are systematically investigated using first principles. Six traditional metals (Sc, In, Ti, Au, Pd, Pt) along with three semimetals (As, Sb, Bi) are chosen as electrodes. At the vertical interface, when traditional metals (Sc, In, Ti, Au, Pd, Pt) are used as electrodes, the PtSe₂ is metallized. However, when semimetals (As, Sb, Bi) are used as electrodes, the band gap of PtSe₂ is preserved, forming the quasi-ohmic contact. At the lateral interface, traditional metals and semimetals form Schottky contacts with Fermi level pinning factors of 0.24 and 0.79 for the hole Schottky barriers, respectively. Compared to traditional metals, the semimetals demonstrate significant advantages in constructing p-type Schottky contacts and suppressing Fermi level pinning. This study offers theoretical support for the development of high-performance devices based on PtSe₂.