Influence of strain distribution on the morphology evolution of a Ge/GeO₂ core/shell nanoparticle confined in ultrathin Al₂O₃ thinfilm by surface oxidation

The influence of strain distribution on morphology evolution of Ge/GeO₂ core/shell nanoparticle confined in ultrathin Al₂O₃ thin film by surface oxidation is investigated. A finite-element simulation is performed to simulate the morphology evolution of the confined Ge/GeO₂ core/shell nanoparticle under the influence of the local strain distribution. It indicates that the resultant oxidation-related morphology of Ge/GeO₂ core/shell nanoparticle confined in ultrathin film is strongly dependent on the local strain distribution. On the other hand, the strain gradients applied on the confined GeO₂ shell can be modified by the formation of polycrystalline GeO₂ shell, which has potential application in tailoring the microstructure and morphology evolution of the Ge/GeO₂ core/shell nanoparticle.