SFB 951 Project A1: Molecular structure of hybrid inorganic/organic systems (HIOS)

Hybrid Inorganic/Organic Systems (HIOS), heterostructures from different materials, currently revolutionize electronic and optical technology. Our long term goal is the exploration of new materials that combine the strengths of organic and inorganic semiconductors and metals as well as their applications.

The optical and electronic properties of HIOS strongly depend on the molecular configuration of the conjugated organic molecules (COMs) at the inorganic semiconductor surfaces.The goal of project A1 is to explore the nucleation and self-assembly of COMs on ZnO surfaces and in bulk crystals by applying atomistically resolved classical molecular dynamics (MD) computer simulations.

 

OBJECTIVES

 

  • Study COM bulk structure formation
  • Investigate interactions at organic/inorganic interfaces and bulk structure deformation near surfaces
  • Find effective COM-COM pair potentials and COM-Surface interactions suitable for coarse graining

Study of COM bulk structure formation: Crystallization of systems composed of a few hundred COMs can be simulated effectively in a matter of days on a local cluster.


METHODS

Highly advanced molecular dynamics software packages auch as GROMACS, coupled with strong computational power, calculate molecular trajectories by integrating Newton’s equations of motion employing intramolecular and intermolecular interactions from force-fields adjusted for organic molecules.

  • Bulk structure: We ascertain the relationship between parameters (such as partial charges, Lennard-Jones parameters, temperature, pressure) and the bulk structure of organic molecular crystals composed of Coronene, Diindenoperylene or p-Sexiphenyl. 
  • Interfaces: We investigate the fundamental interactions governing nucleation of COMs on inorganic surfaces and study structure-dependence on temperature and coverage. Refined input parameters (partial charges, Lennard-Jones parameters)  will be provided from density functional theory (projects A4, B4). Results will be compared to X-ray scattering experiments (A9) and equilibrated structures will be proposed for ab-initio calculations (A4, B4, B6).
  • Coarse Graining: Effective COM-COM pair potentials and COM-Surface interactions suitable for coarse graining (A7) can be calculated with simulation techniques based on AFM theory.

This work is financially supported by the DFG within the framework of the Collaborative Research Centre SFB 951 .