Efficient hierarchical models for reactivity of organic layers on semiconductor surfaces. Issue 12 (22nd February 2021) - Luy, Jan‐Niclas
Abstract: Computational modeling of organic interface formation on semiconductors poses a challenge to a density functional theory‐based description due to structural and chemical complexity. A hierarchical approach is presented, where parts of the interface are successively removed in order to increase computational efficiency while maintaining the necessary accuracy. First, a benchmark is performed to probe the validity of this approach for three model reactions and five dispersion corrected density functionals. Reaction energies are generally well reproduced by generalized gradient approximation‐type functionals but accurate reaction barriers require the use of hybrid functionals. Best performance is found for the model system that does not explicitly consider the substrate but includes its templating effects. Finally, this efficient model is used to provide coverage dependent reaction energies and suggest synthetic principles for the prevention of unwanted growth termination reactions for organic layers on semiconductor surfaces. Abstract : A hierarchical approach for modeling organic interface formation on semiconductors is presented. The largest model system (rank 1) constituting the full interface is computationally very demanding. By removing parts of the interface such as substrate or neighboring molecules from computations, properties of interest can be more efficiently calculated while retaining acceptable accuracy.