Adhesion, Stability and Electronic Properties of Ag/SnO2 Interface from First-Principles Calculation

Abstract

The interfacial bonding state between each oxide and the silver matrix in AgCuOIn₂O₃SnO₂ electrical contact materials remains unclear. To address this, first-principles calculations using density-functional theory are employed to establish the low-index surfaces of Ag and SnO₂ and perform convergence tests. Computational results reveal that the Ag (111) surface and the SnO₂(110)-O surface exhibit the highest stability among their respective low-index surfaces. Consequently, these surfaces are chosen to form the interfacial model, and their atomic structure, adhesion work, and interfacial energies are systematically analyzed. The results demonstrate that the stability and interfacial bonding strength of the Ag(111)/SnO₂(110)-O interface are high, exhibiting metallic properties and strong conductivity. Moreover, at an interface spacing of d₀ = 2.4 Å, the interface stability is optimal. The redistribution of charge at the interface induces significant changes in the local atomic density of states, particularly noticeable in the Ag and O atoms. Additionally, the Ag/SnO₂ interface is predominantly bonded through ionic interactions, contributing to its robust bonding.