Density Functional Theory Study of Atomic Layer Deposition of Zinc Oxide on Graphene

Abstract

The dissociation of zinc ions (Zn 2+) from vapor-phase zinc acetylacetonate, Zn(C 5 H 7 O 2) 2, or Zn(acac) 2 and its adsorption onto graphene oxide via atomic layer deposition (ALD) were studied using a quantum mechanics approach. Density functional theory (DFT) was used to obtain an approximate solution to the Schrödinger equation. The graphene oxide cluster model was used to represent the surface of the graphene film after pre-oxidation. In this study, the geometries of reactants, transition states, and products were optimized using the B3LYB/6-31G** level of theory or higher. Furthermore, the relative energies of the various intermediates and products in the gas-phase radical mechanism were calculated at the B3LYP/6-311++G** and MP2/6-311 + G(2df,2p) levels of theory. Additionally, a molecular orbital (MO) analysis was performed for the products of the decomposition of the Zn(acac) 2 complex to investigate the dissociation of Zn 2+ and the subsequent adsorption of H atoms on the C 5 H 7 O 2 cluster to form acetylacetonate enol. The reaction energies were calculated, and the reaction mechanism was accordingly proposed. A simulation of infrared (IR) properties was performed using the same approach to support the proposed mechanism via a complete explanation of bond forming and breaking during each reaction step.