A first-principles investigation of the intrinsic electronic properties and strain engineering in two-dimensional few-layer noble metals.

Abstract

In this work, first-principles calculations based on density functional theory (DFT) and ab initio molecular dynamics (AIMD) are performed to systematically examine the structural stability, electronic properties, and strain responses of two-dimensional Au, Ag, and Cu few-layers. The calculated binding energies, phonon dispersion spectra, and elastic constants consistently demonstrate that all investigated configurations possess robust thermodynamic, dynamic, and mechanical stability. The electronic structures exhibit distinct layer- and stacking-dependent characteristics governed by interlayer coupling. This behavior is accompanied by systematic shifts in orbital hybridization profiles and the corresponding d-band density of states. Furthermore, the impacts of external in-plane strain on the structural configurations and electronic properties of these noble metal few-layers were comprehensively investigated. The application of in-plane strain acts as a continuous tuning mechanism for the interlayer spacing, reshaping the electronic bands and spatial orbital overlap. This lattice deformation drives significant shifts in the d-band density of states and modulates the mechanical response profiles. These findings establish a comprehensive understanding of the structure-property relationships and strain response mechanisms in two-dimensional noble metals, offering critical theoretical guidelines for their deployment in catalysis, flexible electronics, and quantum functional devices.