Thickness-Dependent Electronic and Transport Properties of PtSe ₂ on Au(111)

Among two-dimensional materials, platinum diselenide (PtSe2) has attracted interest for applications in electronic devices such as transistors and sensors, mainly due to the thickness dependence of its bandgap. Thus, understanding electronic confinement and transport properties in contact with metals is essential for device design. Here, using density functional theory, we investigated the structural, electronic, and electronic transport properties of monolayer (ML), bilayer (BL), and trilayer (TL) PtSe2 on Au(111), PtSe2-X/Au (X = ML, BL, TL). We find the emergence of a chemical interaction at the interface, leading to (i) ohmic contact, (ii) hole doping of PtSe2, and (iii) metallization of the contact layer. In PtSe2-ML/Au, the semiconductor ML becomes metallic, while in PtSe2–BL/Au and PtSe2-TL/Au, the top layers, which do not directly contact Au, become semimetallic. Transport calculations further reveal a thickness-dependent behavior of the electronic transmittance and Schottky barriers along the PtSe2-X channels in contact with the PtSe2-X/Au(111) leads. Based on this atomistic understanding, we propose a heterostructure, Au/PtSe2-TL/Au, where a metal–semiconductor transition can be tuned by mechanical strain. These results highlight the potential of few-layer PtSe2 for two-dimensional electronic devices.