Contact tuning at monolayer AlSiTe3-metal interfaces: Schottky barriers and Fermi-level pinning

Abstract

Driven by the demand for high-performance nanoscale devices, the two-dimensional layered material AlSiTe 3, featuring tunable electronic structure and excellent thermoelectric and optoelectronic properties, exhibits significant application potential. In this work, we perform first-principles calculations to systematically investigate the interface electronic structure, Schottky barrier height (SBH), and Fermi-level pinning (FLP) of monolayer AlSiTe 3 in contact with metals including Ba, Sc, Eu, Mg, Zr, Pb, Hf, Be, and Ni. The results reveal that metal-induced gap states and interfacial charge transfer strongly influence the electronic properties at the interface. The calculated n- and p-type SBH values indicate pronounced FLP, with pinning factors Sn=0.265 and Sp=0.269. Moreover, vertical strain, an external electric field, magnetic metals, and layer-number engineering can effectively modulate the contact type and SBH, enabling transitions from Schottky to ohmic contact. These findings provide a theoretical basis for the design of metal contacts in low-power AlSiTe 3-based electronic devices.