Numerical Analysis of ZnO Thin Film Crystallographic Stability on Metal Substrates

Abstract

Salah Uddin and Md. Miraj Hossain

We present a density functional theory (DFT) investigation of the crystallographic stability and formation energetics of ultrathin ZnO films on Ag(111), Ag(001), and Pt(001) metal substrates. DFT calculations using the Vienna Ab Initio Simulation Package (VASP) with the Perdew−Burke−Ernzerhof (PBE) exchange-correlation functional and Grimme D2 dispersion correction predict that the ZnO film structure is governed jointly by the substrate surface symmetry and the film/substrate lattice mismatch. The relative formation energy per unit area systematically favors wurtzite (O-terminated, Epoxa/c/A = −83.6 meV/Å2) on Ag(111) and zinc-blende (O-terminated, Epoxa/c/A = −160.4 meV/Å2) on Pt(001). These findings are in quantitative agreement with experimental observations from HRTEM and LEED, establishing clear design rules for engineering ZnO phase selection via substrate choice.

PDF